Knowledge (XXG)

Composition (combinatorics)

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310: 77: 329: 150: 171: 448: 923: 1084: 641: 744: 1273: 115:
of a weak composition is usually not considered to define a different weak composition; in other words, weak compositions are assumed to be implicitly extended indefinitely by terms 0.
65:
of that number. Every integer has finitely many distinct compositions. Negative numbers do not have any compositions, but 0 has one composition, the empty sequence. Each positive integer
369: 1325: 536: 768: 1352: 1185: 1115: 352:
Conventionally the empty composition is counted as the sole composition of 0, and there are no compositions of negative integers. There are 2 compositions of
962: 111:. As a consequence every positive integer admits infinitely many weak compositions (if their length is not bounded). Adding a number of terms 0 to the 61:. Two sequences that differ in the order of their terms define different compositions of their sum, while they are considered to define the same 1461: 270:
It is possible to put constraints on the parts of the compositions. For example the five compositions of 5 into distinct terms are:
548: 1367: 649: 1434: 28: 1214: 1500: 465: − 1 binary choices, the result follows. The same argument shows that the number of compositions of 443:{\displaystyle {\big (}\,\overbrace {1\,\square \,1\,\square \,\ldots \,\square \,1\,\square \,1} ^{n}\,{\big )}} 538:. Note that by summing over all possible numbers of parts we recover 2 as the total number of compositions of 1396: 1278: 1405: 1188: 1354:
are allowed to be zero, then the number of such monomials is exactly the number of weak compositions of
918:{\displaystyle a_{1}+a_{2}+\ldots +a_{k}=n+k\quad \mapsto \quad (a_{1}-1)+(a_{2}-1)+\ldots +(a_{k}-1)=n} 84: 486: 481: 322: 108: 1410: 333: 309: 133:
of the (nonnegative or positive) integers, is an ordered collection of one or more elements in
1457: 62: 1467: 1426: 58: 1330: 1128: 1093: 328: 76: 17: 1471: 1391: 1387: 1494: 1079:{\displaystyle {\binom {k}{n}}_{(1)_{a\in A}}=\left(\sum _{a\in A}x^{a}\right)^{k}} 1087: 149: 35: 170: 1456:. Discrete Mathematics and its Applications. Boca Raton, Florida: CRC Press. 1427:"Restricted weighted integer compositions and extended binomial coefficients" 80: 54: 1485: 103:, but allowing terms of the sequence to be zero: it is a way of writing 1211:
parts. In fact, a basis for the space is given by the set of monomials
43: 928:
It follows from this formula that the number of weak compositions of
959:
parts is given by the extended binomial (or polynomial) coefficient
327: 308: 169: 148: 75: 290:
Compare this with the three partitions of 5 into distinct terms:
461:
determines an assignment of pluses and commas. Since there are
1086:, where the square brackets indicate the extraction of the 636:{\displaystyle \sum _{k=1}^{n}{n-1 \choose k-1}=2^{n-1}.} 951:-restricted compositions, the number of compositions of 344:
the number of ways one can ascend a staircase of length
1333: 1281: 1217: 1131: 1096: 965: 771: 739:{\displaystyle {n+k-1 \choose k-1}={n+k-1 \choose n}} 652: 551: 489: 372: 359:
Placing either a plus sign or a comma in each of the
1346: 1319: 1267: 1179: 1109: 1078: 917: 738: 635: 530: 442: 1394:(2004). "Compositions of n with parts in a set". 1268:{\displaystyle x_{1}^{d_{1}}\cdots x_{n}^{d_{n}}} 983: 970: 730: 703: 691: 656: 605: 576: 522: 493: 936:parts equals the number of weak compositions of 336:to count the {1, 2}-restricted compositions of 435: 375: 244:Compare this with the seven partitions of 5: 8: 1452:Heubach, Silvia; Mansour, Toufik (2009). 1409: 1338: 1332: 1305: 1286: 1280: 1257: 1252: 1247: 1232: 1227: 1222: 1216: 1171: 1161: 1142: 1130: 1101: 1095: 1070: 1059: 1043: 1024: 1000: 989: 982: 969: 967: 964: 894: 863: 838: 808: 789: 776: 770: 729: 702: 700: 690: 655: 653: 651: 618: 604: 575: 573: 567: 556: 550: 521: 492: 490: 488: 434: 433: 432: 426: 416: 412: 408: 404: 400: 396: 392: 388: 382: 380: 374: 373: 371: 363: − 1 boxes of the array 1454:Combinatorics of Compositions and Words 1379: 356: ≥ 1; here is a proof: 1203:is the number of weak compositions of 1320:{\displaystyle d_{1}+\ldots +d_{n}=d} 646:For weak compositions, the number is 27:For other uses of "Composition", see 7: 1486:Partition and composition calculator 1117:in the polynomial that follows it. 457:. Conversely, every composition of 348:, taking one or two steps at a time 191:The sixteen compositions of 5 are: 1125:The dimension of the vector space 974: 758:corresponds to a weak one of  707: 660: 580: 497: 321: +1 ordered partitions form 25: 531:{\displaystyle {n-1 \choose k-1}} 453:produces a unique composition of 830: 826: 313:The numbers of compositions of 99:is similar to a composition of 1368:Stars and bars (combinatorics) 1168: 1135: 1030: 1017: 997: 990: 906: 887: 875: 856: 850: 831: 827: 1: 1435:Journal of Integer Sequences 107:as the sum of a sequence of 57:of a sequence of (strictly) 29:Composition (disambiguation) 18:Composition (number theory) 1517: 118:To further generalize, an 26: 1199:variables over the field 153:The 32 compositions of 6 1121:Homogeneous polynomials 123:-restricted composition 73:distinct compositions. 1425:Eger, Steffen (2013). 1397:Congressus Numerantium 1348: 1327:. Since the exponents 1321: 1269: 1189:homogeneous polynomial 1181: 1111: 1080: 919: 740: 637: 572: 532: 444: 349: 325: 305:Number of compositions 188: 174:The 11 partitions of 6 167: 88: 1349: 1347:{\displaystyle d_{i}} 1322: 1270: 1182: 1180:{\displaystyle K_{d}} 1112: 1110:{\displaystyle x^{n}} 1081: 920: 741: 638: 552: 533: 445: 331: 312: 177:1 + 1 + 1 + 1 + 1 + 1 173: 156:1 + 1 + 1 + 1 + 1 + 1 152: 109:non-negative integers 87:and compositions of 4 79: 1331: 1279: 1215: 1129: 1094: 963: 769: 650: 549: 487: 482:binomial coefficient 370: 49:is a way of writing 1264: 1239: 1501:Integer partitions 1344: 1317: 1265: 1243: 1218: 1177: 1107: 1076: 1054: 915: 736: 633: 528: 480:) is given by the 440: 350: 334:Fibonacci sequence 326: 266:1 + 1 + 1 + 1 + 1. 240:1 + 1 + 1 + 1 + 1. 189: 168: 89: 1463:978-1-4200-7267-9 1039: 981: 940:− 1 into exactly 728: 689: 603: 520: 431: 424: 323:Pascal's triangle 179:2 + 1 + 1 + 1 + 1 160:1 + 2 + 1 + 1 + 1 158:2 + 1 + 1 + 1 + 1 63:integer partition 59:positive integers 16:(Redirected from 1508: 1475: 1444: 1443: 1431: 1422: 1416: 1415: 1413: 1384: 1353: 1351: 1350: 1345: 1343: 1342: 1326: 1324: 1323: 1318: 1310: 1309: 1291: 1290: 1274: 1272: 1271: 1266: 1263: 1262: 1261: 1251: 1238: 1237: 1236: 1226: 1186: 1184: 1183: 1178: 1176: 1175: 1166: 1165: 1147: 1146: 1116: 1114: 1113: 1108: 1106: 1105: 1085: 1083: 1082: 1077: 1075: 1074: 1069: 1065: 1064: 1063: 1053: 1029: 1028: 1013: 1012: 1011: 1010: 988: 987: 986: 973: 924: 922: 921: 916: 899: 898: 868: 867: 843: 842: 813: 812: 794: 793: 781: 780: 750:-composition of 745: 743: 742: 737: 735: 734: 733: 724: 706: 696: 695: 694: 688: 677: 659: 642: 640: 639: 634: 629: 628: 610: 609: 608: 602: 591: 579: 571: 566: 537: 535: 534: 529: 527: 526: 525: 519: 508: 496: 449: 447: 446: 441: 439: 438: 430: 425: 420: 383: 381: 379: 378: 343: 93:weak composition 72: 21: 1516: 1515: 1511: 1510: 1509: 1507: 1506: 1505: 1491: 1490: 1482: 1464: 1451: 1448: 1447: 1429: 1424: 1423: 1419: 1411:10.1.1.484.5148 1392:Mansour, Toufik 1388:Heubach, Silvia 1386: 1385: 1381: 1376: 1364: 1334: 1329: 1328: 1301: 1282: 1277: 1276: 1253: 1228: 1213: 1212: 1167: 1157: 1138: 1127: 1126: 1123: 1097: 1092: 1091: 1055: 1038: 1034: 1033: 1020: 996: 968: 966: 961: 960: 890: 859: 834: 804: 785: 772: 767: 766: 708: 701: 678: 661: 654: 648: 647: 614: 592: 581: 574: 547: 546: 509: 498: 491: 485: 484: 384: 368: 367: 341: 317: +1 into 307: 186: 184: 182: 180: 178: 176: 175: 165: 163: 161: 159: 157: 155: 154: 147: 129:, for a subset 70: 32: 23: 22: 15: 12: 11: 5: 1514: 1512: 1504: 1503: 1493: 1492: 1489: 1488: 1481: 1480:External links 1478: 1477: 1476: 1462: 1446: 1445: 1417: 1378: 1377: 1375: 1372: 1371: 1370: 1363: 1360: 1341: 1337: 1316: 1313: 1308: 1304: 1300: 1297: 1294: 1289: 1285: 1260: 1256: 1250: 1246: 1242: 1235: 1231: 1225: 1221: 1174: 1170: 1164: 1160: 1156: 1153: 1150: 1145: 1141: 1137: 1134: 1122: 1119: 1104: 1100: 1073: 1068: 1062: 1058: 1052: 1049: 1046: 1042: 1037: 1032: 1027: 1023: 1019: 1016: 1009: 1006: 1003: 999: 995: 992: 985: 980: 977: 972: 926: 925: 914: 911: 908: 905: 902: 897: 893: 889: 886: 883: 880: 877: 874: 871: 866: 862: 858: 855: 852: 849: 846: 841: 837: 833: 829: 825: 822: 819: 816: 811: 807: 803: 800: 797: 792: 788: 784: 779: 775: 732: 727: 723: 720: 717: 714: 711: 705: 699: 693: 687: 684: 681: 676: 673: 670: 667: 664: 658: 644: 643: 632: 627: 624: 621: 617: 613: 607: 601: 598: 595: 590: 587: 584: 578: 570: 565: 562: 559: 555: 524: 518: 515: 512: 507: 504: 501: 495: 451: 450: 437: 429: 423: 419: 415: 411: 407: 403: 399: 395: 391: 387: 377: 306: 303: 302: 301: 298: 295: 288: 287: 284: 281: 278: 275: 268: 267: 264: 261: 258: 255: 252: 249: 242: 241: 238: 235: 232: 229: 226: 223: 220: 217: 214: 211: 208: 205: 202: 199: 196: 146: 143: 125:of an integer 95:of an integer 85:binary numbers 83:between 3 bit 24: 14: 13: 10: 9: 6: 4: 3: 2: 1513: 1502: 1499: 1498: 1496: 1487: 1484: 1483: 1479: 1473: 1469: 1465: 1459: 1455: 1450: 1449: 1441: 1437: 1436: 1428: 1421: 1418: 1412: 1407: 1403: 1399: 1398: 1393: 1389: 1383: 1380: 1373: 1369: 1366: 1365: 1361: 1359: 1357: 1339: 1335: 1314: 1311: 1306: 1302: 1298: 1295: 1292: 1287: 1283: 1258: 1254: 1248: 1244: 1240: 1233: 1229: 1223: 1219: 1210: 1206: 1202: 1198: 1194: 1190: 1172: 1162: 1158: 1154: 1151: 1148: 1143: 1139: 1132: 1120: 1118: 1102: 1098: 1089: 1071: 1066: 1060: 1056: 1050: 1047: 1044: 1040: 1035: 1025: 1021: 1014: 1007: 1004: 1001: 993: 978: 975: 958: 955:into exactly 954: 950: 945: 943: 939: 935: 932:into exactly 931: 912: 909: 903: 900: 895: 891: 884: 881: 878: 872: 869: 864: 860: 853: 847: 844: 839: 835: 823: 820: 817: 814: 809: 805: 801: 798: 795: 790: 786: 782: 777: 773: 765: 764: 763: 761: 757: 754: +  753: 749: 746:, since each 725: 721: 718: 715: 712: 709: 697: 685: 682: 679: 674: 671: 668: 665: 662: 630: 625: 622: 619: 615: 611: 599: 596: 593: 588: 585: 582: 568: 563: 560: 557: 553: 545: 544: 543: 541: 516: 513: 510: 505: 502: 499: 483: 479: 477: 472: 469:into exactly 468: 464: 460: 456: 427: 421: 417: 413: 409: 405: 401: 397: 393: 389: 385: 366: 365: 364: 362: 357: 355: 347: 339: 335: 330: 324: 320: 316: 311: 304: 299: 296: 293: 292: 291: 285: 282: 279: 276: 273: 272: 271: 265: 263:2 + 1 + 1 + 1 262: 259: 256: 253: 250: 247: 246: 245: 239: 237:1 + 1 + 1 + 2 236: 234:1 + 1 + 2 + 1 233: 230: 228:1 + 2 + 1 + 1 227: 224: 221: 218: 216:2 + 1 + 1 + 1 215: 212: 209: 206: 203: 200: 197: 194: 193: 192: 181:3 + 1 + 1 + 1 172: 151: 144: 142: 140: 137:whose sum is 136: 132: 128: 124: 122: 116: 114: 110: 106: 102: 98: 94: 86: 82: 78: 74: 68: 64: 60: 56: 52: 48: 45: 41: 37: 30: 19: 1453: 1439: 1433: 1420: 1401: 1395: 1382: 1355: 1208: 1204: 1200: 1196: 1192: 1124: 956: 952: 948: 946: 941: 937: 933: 929: 927: 762:by the rule 759: 755: 751: 747: 645: 539: 478:-composition 475: 474: 470: 466: 462: 458: 454: 452: 360: 358: 353: 351: 345: 342:for example, 337: 318: 314: 289: 269: 243: 190: 138: 134: 130: 126: 120: 119: 117: 112: 104: 100: 96: 92: 90: 66: 50: 46: 39: 33: 1088:coefficient 944:+ 1 parts. 40:composition 36:mathematics 1472:1184.68373 1374:References 1275:such that 1191:of degree 332:Using the 1406:CiteSeerX 1404:: 33–51. 1296:… 1241:⋯ 1152:… 1048:∈ 1041:∑ 1005:∈ 901:− 882:… 870:− 845:− 828:↦ 799:… 719:− 683:− 672:− 623:− 597:− 586:− 554:∑ 514:− 503:− 473:parts (a 422:⏞ 414:◻ 406:◻ 402:… 398:◻ 390:◻ 260:2 + 2 + 1 257:3 + 1 + 1 231:1 + 1 + 3 225:1 + 2 + 2 222:1 + 3 + 1 213:2 + 1 + 2 210:2 + 2 + 1 204:3 + 1 + 1 81:Bijection 1495:Category 1362:See also 145:Examples 53:as the 44:integer 1470:  1460:  1408:  300:3 + 2. 286:1 + 4. 42:of an 1430:(PDF) 1207:into 297:4 + 1 283:2 + 3 280:3 + 2 277:4 + 1 254:3 + 2 251:4 + 1 219:1 + 4 207:2 + 3 201:3 + 2 198:4 + 1 185:3 + 3 183:. . . 164:1 + 5 162:. . . 1458:ISBN 947:For 69:has 38:, a 1468:Zbl 1402:168 1195:in 1187:of 1090:of 113:end 55:sum 34:In 1497:: 1466:. 1440:16 1438:. 1432:. 1400:. 1390:; 1358:. 542:: 340:, 141:. 91:A 1474:. 1442:. 1414:. 1356:d 1340:i 1336:d 1315:d 1312:= 1307:n 1303:d 1299:+ 1293:+ 1288:1 1284:d 1259:n 1255:d 1249:n 1245:x 1234:1 1230:d 1224:1 1220:x 1209:n 1205:d 1201:K 1197:n 1193:d 1173:d 1169:] 1163:n 1159:x 1155:, 1149:, 1144:1 1140:x 1136:[ 1133:K 1103:n 1099:x 1072:k 1067:) 1061:a 1057:x 1051:A 1045:a 1036:( 1031:] 1026:n 1022:x 1018:[ 1015:= 1008:A 1002:a 998:) 994:1 991:( 984:) 979:n 976:k 971:( 957:k 953:n 949:A 942:n 938:k 934:k 930:n 913:n 910:= 907:) 904:1 896:k 892:a 888:( 885:+ 879:+ 876:) 873:1 865:2 861:a 857:( 854:+ 851:) 848:1 840:1 836:a 832:( 824:k 821:+ 818:n 815:= 810:k 806:a 802:+ 796:+ 791:2 787:a 783:+ 778:1 774:a 760:n 756:k 752:n 748:k 731:) 726:n 722:1 716:k 713:+ 710:n 704:( 698:= 692:) 686:1 680:k 675:1 669:k 666:+ 663:n 657:( 631:. 626:1 620:n 616:2 612:= 606:) 600:1 594:k 589:1 583:n 577:( 569:n 564:1 561:= 558:k 540:n 523:) 517:1 511:k 506:1 500:n 494:( 476:k 471:k 467:n 463:n 459:n 455:n 436:) 428:n 418:1 410:1 394:1 386:1 376:( 361:n 354:n 346:n 338:n 319:k 315:n 294:5 274:5 248:5 195:5 187:6 166:6 139:n 135:A 131:A 127:n 121:A 105:n 101:n 97:n 71:2 67:n 51:n 47:n 31:. 20:)

Index

Composition (number theory)
Composition (disambiguation)
mathematics
integer
sum
positive integers
integer partition

Bijection
binary numbers
non-negative integers



Pascal's triangle

Fibonacci sequence
binomial coefficient
coefficient
homogeneous polynomial
Stars and bars (combinatorics)
Heubach, Silvia
Mansour, Toufik
Congressus Numerantium
CiteSeerX
10.1.1.484.5148
"Restricted weighted integer compositions and extended binomial coefficients"
Journal of Integer Sequences
ISBN
978-1-4200-7267-9

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