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Talk:Champernowne constant

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the correct decmial place, and we have 10203040.506070809101112... Now adjust it to get the first few digits right (which involves subtracting exactly 10203040.38261402), and we end up with 60499999499/490050000000 - which is indeed the 18th convergent of the continued fraction for Champernowne's constant. In a similar way we could construct an approximation which went as far as the end of the 3-digit numbers, with a denominator only barely larger than that required to specify the 2-digit section, and so on. That's
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Of course my program could be faulty - the page itself does mention that Champernowne's constant can stress naive continued-fraction calculation code - but I have two reasons to think it isn't faulty: firstly, the two previous very large terms start "457" and "4457", making me willing to believe that
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include those cases), say at 5 googol, we'd have more digits 1 to 4 than 5 to 9, but as we look at more and more decimals, these fluctuations start to "drown" in a "sea" of equifrequent trailing digits. Googol (included) to 5 googol (excluded) would contribute a total of 404 (no pun intended) googol
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So we can use this fact to directly construct a very good approximation to Champernowne's constant which goes as far as (for example) the end of the 2-digit numbers. Simply start with 1/99^2, which actually contains the digit sequence 10111213...9697. Then multiply by 10^11 to bring that sequence to
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If this is the case, then I am not sure what approach should be used to rectify the situation. I assume that the original author of the graphs intended to use the log scale graph to include all of the points that are off scale on the linear graph. Going to 10 would greatly compress the scale of the
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These don't approximate the Champernowne number, but we can count all digits except 0 easily and find that there are exactly (n/10) 10^n of each. The '0' digits are a bit nonstandard here, and when written in standard form, C, Ch, Cha... lose exactly n of them because they appear before the decimal
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The article says this number is "obviously" normal in base 10, which I know means all the digits occur with equal frequency. However, after the first 190 digits, 0.12345678910111213...9899, the digit 0 has occurred much less than the others because we do not write 01, 02, 03 etc. The same is true
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I think the nice image here containing the continued fraction terms is incorrect in the last partial term. I rediscovered this curious continued fraction for myself recently after writing a small program which accepted an infinite decimal expansion on standard input and produced its continued
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Also, I believe I understand why those extremely large terms show up in the expansion. However, I hesitate to add it to the page, because it might constitute original research (I thought of it for myself). On the other hand, it's pretty simple and was instantly obvious to me on examining the
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I just did some calculations. Let P(N) be the proportion of 0's in the concatenation of the integers 1 to N inclusive. Then P(9) = 0, P(99) = 0.047619047619, P(999) = 0.0654205607477, P(9,999) = 0.0742883591761, P(99,999) = 0.0795456637396, P(999,999) = 0.0830188852261, P(9,999,999) =
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While solving a Project Euler problem, I came up with an alternative expression for the Champernowne constant in base 10, which I think is a little easier to read than the one given. I think it can also be easily generalized to other bases. Here's the expression:
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The decimal expansion of 1/99^2 is 0.0001020304..., that of 1/999^2 is 0.000001002003004..., and in general the expansion of 1/(10^n-1)^2 consists of a sequence of integers incrementing from zero at each n-digit position. (You can check this by working out
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On to the differences between digits of C, Ch, Cha... and the Champernowne number: The latter doesn't use fixed-length numbers, but omits all leading 0 digits, of which there are none in C, 10 in Ch, 10+100 in Cha, and generally (10^n-10) / 9 in the
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I think we should say a few more sentences about the normalization of C10 in the article, but that would require an already published accessible (both in language that's easy to understand, and available free of charge) proof somewhere else as a
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I think that there is an error in the log scale graph of the continued fraction coefficients. The term at position 41 has 2504 decimal digits , so I think that the point for position 41 should be near 10 instead of 10.
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Is this formula (which is quite easy to derive, and therefore probably already well-known to mathematicians) worth including in the article? An advantage of this formula is that it enables one to efficiently find the
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as a GP of GPs.) Of course the pattern in each of these expansions breaks once the integers start carrying from one n-digit segment into the previous one, and being rational they must end up repeating somehow.
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digits: 40 googol '0' digits, (40+1) googol digits 1 to 4 each, and 40 googol digits 5 to 9. Again, deviations from equifrequency are within O(m) if we stop at m, and average digit frequencies are O(m log m).
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In reply to the section creator, and working out a formula in support of DanBishop's argument, the "best" proof I could think of is to construct similar numbers C, Ch, Cha, Cham, Champ, etc. defined as
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fraction terms on standard output as they became uniquely determined; but my program says that the 163rd term begins "44457", not "40012" as claimed in the picture on this page.
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after we add all the 3-digit numbers, all the 4-digit numbers and so on. Why it is "obvious" that the probability of a random digit being 0 eventually catches up, so to speak?
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Of course. I was specifically addressing the OP's "cut the number off after X digits" approach, and why that's exactly never going to give you 1/10 for the frequencies.
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there are extremely good approximations available for this number, and hence why the continued fraction contains very large terms after each of them.
1086:{\displaystyle C_{m}=\sum _{n=1}^{\infty }{\frac {n}{10_{m}^{~\left(\sum \limits _{k=1}^{n}\left\lceil \log _{10_{m}}(k+1)\right\rceil \right)}}}} 234:
convergents, so perhaps it's not original enough to be a problem. I'd like a judgment call from an experienced Wikipedian, if one is available.
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will give the same answer as I got! But if someone disagrees with my result, they might wish to point out to me where the bug is.)
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is even; obviously, the sequence contains an infinite number of odd and even numbers, yet the odd terms occur with twice the
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which agrees to the last digit with my 163rd term and not with the one here. (That page, incidentally, also shows the
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Excellent question. I suppose it has something to do with leading digits mattering less as the numbers get longer.
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log graph, but keeping the scale as it is would mean that the point at position 41 is off scale.
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on Knowledge. If you would like to participate, please visit the project page, where you can join
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Finally, if we truncate elsewhere (not at a power of 10 - and a complete proof of normality
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Champ = 00000.00001 00002 00003 00004 00005 00006 00007 00008 00009 00010...99998 99999...
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th decimal digit in the constant without directly finding the preceding digits.
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ludicrously large number starting with "444457", continuing the pattern.)
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Am I correct, and if so, does anyone have any ideas on the best remedy?
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is normal, then the proportional of zero digits should have a limit of
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of each digit. Consider a infinite sequence composed of the terms
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Can someone start a section giving the uses of this number?
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10^n) and becomes negligible for truly long excerpts of C10.
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I confirmed that the image was incorrect and removed it.
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of the even terms. If the decimal Champernowne constant
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So I've prepared a replacement image and uploaded it to
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the next one starts "44457", and secondly I googled up
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This is similar to the argument that the integers are
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point. (But n in (n/10)10^n soon becomes negligible.)
247: 101:, a collaborative effort to improve the coverage of 1085: 893: 869: 849: 823: 728: 303:{\displaystyle \sum _{i=0}^{\infty }10^{-(i+1)n}i} 302: 407:Yes, but that does not say anything about the 8: 538:Ch = 00.0102030405060708091011...979899, ... 19: 47: 1043: 1038: 1023: 1012: 1000: 995: 986: 980: 969: 956: 950: 886: 862: 857:is defined to be the number of digits in 836: 805: 785: 779: 741: 709: 700: 694: 683: 670: 664: 273: 263: 252: 246: 532:the sum of 10^n terms (k / 10^kn). E.g. 924: 49: 558:That grows like O(10^n) rather than O( 493:increases, which it appears to do. β€” 7: 95:This article is within the scope of 1009: 338:Something that's always bothered me 38:It is of interest to the following 981: 695: 652:Alternative expression in base 10? 337: 264: 14: 1125:Low-priority mathematics articles 115:Knowledge:WikiProject Mathematics 1120:Start-Class mathematics articles 489:) above increase towards 0.1 as 118:Template:WikiProject Mathematics 82: 72: 51: 20: 590:Formatting and decimals fixed. 135:This article has been rated as 1066: 1054: 773: 761: 752: 746: 719: 713: 289: 277: 1: 521:09:34, 23 November 2012 (UTC) 353:01:54, 24 November 2007 (UTC) 109:and see a list of open tasks. 158:Error in continued fraction? 914:21:54, 11 August 2016 (UTC) 647:04:02, 23 August 2013 (UTC) 383:21:32, 30 August 2009 (UTC) 368:21:06, 30 August 2009 (UTC) 237:My argument is as follows: 1141: 333:08:05, 29 April 2007 (UTC) 222:01:19, 2 August 2011 (UTC) 201:08:05, 29 April 2007 (UTC) 625:Error in log scale graph? 600:14:02, 8 March 2019 (UTC) 586:07:03, 8 March 2019 (UTC) 503:20:28, 25 July 2012 (UTC) 134: 67: 46: 1106:13:15, 6 July 2017 (UTC) 620:14:16, 2 June 2013 (UTC) 402:04:52, 29 May 2012 (UTC) 141:project's priority scale 932:http://oeis.org/A143534 98:WikiProject Mathematics 1087: 1028: 985: 895: 871: 851: 825: 730: 699: 304: 268: 229:Reason for large terms 28:This article is rated 1088: 1008: 965: 896: 872: 852: 826: 731: 679: 305: 248: 949: 885: 861: 835: 740: 663: 409:relative frequencies 245: 121:mathematics articles 1080: 850:{\displaystyle n+1} 1083: 991: 891: 867: 847: 821: 726: 300: 90:Mathematics portal 34:content assessment 1081: 1002: 945:Could I add that 894:{\displaystyle n} 870:{\displaystyle m} 813: 800: 724: 456:are odd and each 373:0.0854838724428. 212:comment added by 155: 154: 151: 150: 147: 146: 1132: 1092: 1090: 1089: 1084: 1082: 1079: 1078: 1074: 1073: 1069: 1050: 1049: 1048: 1047: 1027: 1022: 1001: 999: 987: 984: 979: 961: 960: 934: 929: 906:Tanmay Mudholkar 900: 898: 897: 892: 876: 874: 873: 868: 856: 854: 853: 848: 830: 828: 827: 822: 814: 806: 801: 796: 795: 780: 735: 733: 732: 727: 725: 723: 722: 701: 698: 693: 675: 674: 535:C = 0.123456789, 480: 479: 475: 448:β‰₯ 0, where each 309: 307: 306: 301: 296: 295: 267: 262: 224: 123: 122: 119: 116: 113: 92: 87: 86: 76: 69: 68: 63: 55: 48: 31: 25: 24: 16: 1140: 1139: 1135: 1134: 1133: 1131: 1130: 1129: 1110: 1109: 1039: 1034: 1033: 1029: 1007: 1003: 952: 947: 946: 943: 938: 937: 930: 926: 921: 883: 882: 859: 858: 833: 832: 781: 738: 737: 705: 666: 661: 660: 654: 627: 608: 477: 473: 472: 470: 443: 432: 421: 340: 269: 243: 242: 231: 207: 160: 120: 117: 114: 111: 110: 88: 81: 61: 32:on Knowledge's 29: 12: 11: 5: 1138: 1136: 1128: 1127: 1122: 1112: 1111: 1077: 1072: 1068: 1065: 1062: 1059: 1056: 1053: 1046: 1042: 1037: 1032: 1026: 1021: 1018: 1015: 1011: 1006: 998: 994: 990: 983: 978: 975: 972: 968: 964: 959: 955: 942: 939: 936: 935: 923: 922: 920: 917: 890: 866: 846: 843: 840: 820: 817: 812: 809: 804: 799: 794: 791: 788: 784: 778: 775: 772: 769: 766: 763: 760: 757: 754: 751: 748: 745: 721: 718: 715: 712: 708: 704: 697: 692: 689: 686: 682: 678: 673: 669: 653: 650: 626: 623: 612:81.129.181.145 607: 604: 603: 602: 588: 575: 571: 563: 556: 555:th of the lot. 548: 544: 543: 542: 539: 536: 530: 526: 525: 524: 523: 513:Law of Entropy 506: 505: 468: 437: 426: 415: 394:Law of Entropy 386: 385: 370: 339: 336: 299: 294: 291: 288: 285: 282: 279: 276: 272: 266: 261: 258: 255: 251: 230: 227: 226: 225: 159: 156: 153: 152: 149: 148: 145: 144: 133: 127: 126: 124: 107:the discussion 94: 93: 77: 65: 64: 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 1137: 1126: 1123: 1121: 1118: 1117: 1115: 1108: 1107: 1103: 1099: 1094: 1075: 1070: 1063: 1060: 1057: 1051: 1044: 1040: 1035: 1030: 1024: 1019: 1016: 1013: 1004: 996: 992: 988: 976: 973: 970: 966: 962: 957: 953: 940: 933: 928: 925: 918: 916: 915: 911: 907: 902: 888: 878: 864: 844: 841: 838: 818: 815: 810: 807: 802: 797: 792: 789: 786: 782: 776: 770: 767: 764: 758: 755: 749: 743: 716: 710: 706: 702: 690: 687: 684: 680: 676: 671: 667: 658: 651: 649: 648: 644: 640: 635: 631: 624: 622: 621: 617: 613: 605: 601: 597: 593: 592:84.140.35.194 589: 587: 583: 579: 578:84.140.35.194 576: 572: 568: 564: 561: 557: 554: 549: 545: 540: 537: 534: 533: 531: 528: 527: 522: 518: 514: 510: 509: 508: 507: 504: 500: 496: 492: 488: 484: 467: 463: 459: 455: 451: 447: 441: 436: 430: 425: 419: 414: 410: 406: 405: 404: 403: 399: 395: 391: 384: 380: 376: 371: 369: 365: 361: 357: 356: 355: 354: 350: 346: 345:91.105.60.254 335: 334: 331: 328: 323: 320: 318: 312: 297: 292: 286: 283: 280: 274: 270: 259: 256: 253: 249: 238: 235: 228: 223: 219: 215: 214:24.19.214.109 211: 205: 204: 203: 202: 199: 196: 191: 189: 185: 181: 179: 175: 173: 169: 164: 157: 142: 138: 132: 129: 128: 125: 108: 104: 100: 99: 91: 85: 80: 78: 75: 71: 70: 66: 60: 57: 54: 50: 45: 41: 35: 27: 23: 18: 17: 1098:Bexandre2002 1095: 944: 941:Infinite sum 927: 903: 879: 659: 655: 639:Aginourmidst 636: 632: 628: 609: 566: 559: 552: 490: 486: 465: 461: 457: 453: 449: 445: 439: 434: 428: 423: 417: 412: 408: 387: 341: 327:Simon Tatham 324: 321: 316: 313: 239: 236: 232: 208:β€” Preceding 195:Simon Tatham 192: 187: 182: 176: 171: 165: 161: 137:Low-priority 136: 96: 62:Low‑priority 40:WikiProjects 112:Mathematics 103:mathematics 59:Mathematics 30:Start-class 1114:Categories 919:References 495:Loadmaster 444:, for all 330:86.6.4.136 198:86.6.4.136 483:DanBishop 462:frequency 390:countable 375:DanBishop 360:DanBishop 210:unsigned 831:; here 574:source. 139:on the 736:where 433:, and 36:scale. 606:Uses? 485:'s P( 1102:talk 910:talk 643:talk 616:talk 596:talk 582:talk 567:must 517:talk 499:talk 452:and 398:talk 379:talk 364:talk 349:talk 218:talk 188:that 172:next 1036:log 317:why 131:Low 1116:: 1104:) 1096:- 1093:? 1052:⁑ 1041:10 1010:βˆ‘ 993:10 982:∞ 967:βˆ‘ 912:) 904:-- 877:. 808:10 783:10 777:βˆ’ 707:10 696:∞ 681:βˆ‘ 672:10 645:) 618:) 598:) 584:) 519:) 501:) 478:10 469:10 442:+2 431:+1 422:, 420:+0 400:) 381:) 366:) 351:) 325:- 275:βˆ’ 271:10 265:∞ 250:βˆ‘ 220:) 193:- 1100:( 1076:) 1071:βŒ‰ 1067:) 1064:1 1061:+ 1058:k 1055:( 1045:m 1031:⌈ 1025:n 1020:1 1017:= 1014:k 1005:( 997:m 989:n 977:1 974:= 971:n 963:= 958:m 954:C 908:( 889:n 865:m 845:1 842:+ 839:n 819:n 816:+ 811:9 803:+ 798:9 793:1 790:+ 787:n 774:) 771:n 768:+ 765:1 762:( 759:m 756:= 753:) 750:m 747:( 744:f 720:) 717:m 714:( 711:f 703:m 691:1 688:= 685:m 677:= 668:C 641:( 614:( 594:( 580:( 560:n 553:n 515:( 497:( 491:N 487:N 476:⁄ 474:1 466:C 458:c 454:b 450:a 446:n 440:n 438:3 435:c 429:n 427:3 424:b 418:n 416:3 413:a 396:( 377:( 362:( 347:( 298:i 293:n 290:) 287:1 284:+ 281:i 278:( 260:0 257:= 254:i 216:( 143:. 42::

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Simon Tatham
86.6.4.136
08:05, 29 April 2007 (UTC)
unsigned
24.19.214.109
talk
01:19, 2 August 2011 (UTC)
Simon Tatham
86.6.4.136
08:05, 29 April 2007 (UTC)
91.105.60.254
talk
01:54, 24 November 2007 (UTC)
DanBishop

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