Knowledge

Talk:Probable prime

Source 📝

81: 71: 53: 22: 248:
The beginning of this article says, "For a fixed base a, it is unusual for a composite number to be a probable prime (that is, a pseudoprime) to that base. For example, there are only 21853 pseudoprimes base 2 that are less than 25*10^9 (see page 1005 of ) and 1091987405 primes less than 25*10^9."
227:
Surely a pseudoprime (for some criterion) is a composite number which passes the criterion. The word 'composite' is missing from this definition. My understanding is that "probable prime" menas a number that passes the criterion; it is very likely to be a prime, but if proved composite is then a
252:
The second sentence has nothing to do with the first: it compares pseudoprimes with primes, not with composites. The relevant comparison is the number of pseudoprimes compared to the number of composite numbers (say, up to 25*10^9). Even more relevant is the number of pseudoprimes compared to the
173:
over the input numbers (prime/composite), but over an additional sequence of "coin tosses" the algorithm does. Thus, a statement like "the algorithm is correct with probability 3/4" does not mean it will miss 1/4 of composites; it means that for any given composite, if you run the algorithm
274:
With n = 25*10^9, the result is that there are 11408012595 odd composite numbers up to 25*10^9, but only 21853 pseudoprimes base 2. So, only about .00019% of odd composites up to 25*10^9 are pseudoprimes base 2.
174:
independently multiple times, about 3/4 of the runs will detect the number as being composite. However, such algorithms often do use some notion of pseudoprimeness; typically, it works by choosing a random
385:
to specify page 1005. The same reference is used several times with different page numbers. Another time, please describe the alleged problem from the beginning. I spent time checking everything.
133: 300: 434: 127: 429: 103: 400: 362: 326: 94: 58: 304: 165:
The paragraph on cryptography is misguided. Typical probabilistic primality testing algorithms (e.g. Rabin-Miller) detect
33: 191: 21: 404: 366: 330: 390: 345: 39: 80: 280: 224:
The main article has: "A strong probable prime to base a is called a strong pseudoprime to base a."
234: 102:
on Knowledge. If you would like to participate, please visit the project page, where you can join
86: 70: 52: 386: 357: 341: 320: 169:
composites, including all sort of pseudoprimes. The probability distribution in question is
354:
Because I read ":1005" at the exponent. I suppose that it is the corruption of a reference.
276: 264:
Floor - 1 = number of odd integers <= n, excluding 1 (1 is neither prime nor composite)
423: 199: 399:
Thanks again. Excuse me, but I am too aged to remain updated with these conventions.
257:
composites because it's easy to determine whether or not an even number is prime.
379: 195: 99: 76: 325:
there should be a misprint soon after "21,853 pseudoprimes base 2". thanks.
408: 394: 370: 349: 334: 308: 284: 237: 210: 183: 290:
Seeing no comments, I put this into the first part of the article.
15: 270:
Floor - 1 - (PrimePi - 1) = number of odd composites <= n
295:
Johasouerp to coumiila Agreed banikcoumilla johasouerport
198:). I would, but I'm not sure how to reword everything. 98:, a collaborative effort to improve the coverage of 244:
Comparing pseudoprime counts with composite numbers
340:It looks right to me. What do you think is wrong? 132:This article has not yet received a rating on the 194:. Feel free to edit the article to fit (and also 220:Is definition of string pseudoprime correct ? 209:OK. I hope the wording is more clear now. -- 8: 19: 267:PrimePi - 1 = number of odd primes <= n 47: 178:, and testing the input for being base- 49: 435:Unknown-priority mathematics articles 7: 92:This article is within the scope of 38:It is of interest to the following 14: 301:2400:C600:338A:90CB:1:0:4DE4:E106 112:Knowledge:WikiProject Mathematics 430:Start-Class mathematics articles 228:pseudoprime for that criterion. 115:Template:WikiProject Mathematics 79: 69: 51: 20: 375:It's a correct reference using 1: 409:07:30, 19 February 2024 (UTC) 395:00:07, 19 February 2024 (UTC) 371:23:27, 18 February 2024 (UTC) 350:21:39, 18 February 2024 (UTC) 335:20:09, 18 February 2024 (UTC) 106:and see a list of open tasks. 192:Miller-Rabin primality test 451: 285:21:06, 30 March 2017 (UTC) 238:12:16, 18 April 2007 (UTC) 299:Jouwelrana 0200019508794 260:In Mathematica notation, 186:09:56, 24 Aug 2004 (UTC) 131: 64: 46: 202:19:55, 2004 Aug 30 (UTC) 134:project's priority scale 309:18:38, 3 May 2023 (UTC) 213:15:19, 1 Sep 2004 (UTC) 190:I've added the link to 95:WikiProject Mathematics 28:This article is rated 118:mathematics articles 87:Mathematics portal 34:content assessment 314:probable misprint 148: 147: 144: 143: 140: 139: 442: 384: 378: 361: 324: 162: 161: 157: 120: 119: 116: 113: 110: 89: 84: 83: 73: 66: 65: 55: 48: 31: 25: 24: 16: 450: 449: 445: 444: 443: 441: 440: 439: 420: 419: 382: 376: 355: 318: 316: 297: 246: 222: 163: 159: 155: 153: 152: 117: 114: 111: 108: 107: 85: 78: 32:on Knowledge's 29: 12: 11: 5: 448: 446: 438: 437: 432: 422: 421: 418: 417: 416: 415: 414: 413: 412: 411: 315: 312: 296: 293: 292: 291: 272: 271: 268: 265: 245: 242: 221: 218: 217: 216: 215: 214: 204: 203: 151: 149: 146: 145: 142: 141: 138: 137: 130: 124: 123: 121: 104:the discussion 91: 90: 74: 62: 61: 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 447: 436: 433: 431: 428: 427: 425: 410: 406: 402: 401:151.29.149.29 398: 397: 396: 392: 388: 381: 374: 373: 372: 368: 364: 363:151.29.149.29 359: 353: 352: 351: 347: 343: 339: 338: 337: 336: 332: 328: 327:151.29.149.29 322: 313: 311: 310: 306: 302: 294: 289: 288: 287: 286: 282: 278: 269: 266: 263: 262: 261: 258: 256: 250: 243: 241: 239: 236: 232: 229: 225: 219: 212: 208: 207: 206: 205: 201: 197: 193: 189: 188: 187: 185: 182:pseudoprime. 181: 177: 172: 168: 158: 150: 135: 129: 126: 125: 122: 105: 101: 97: 96: 88: 82: 77: 75: 72: 68: 67: 63: 60: 57: 54: 50: 45: 41: 35: 27: 23: 18: 17: 317: 298: 273: 259: 254: 251: 247: 233: 230: 226: 223: 179: 175: 170: 166: 164: 93: 40:WikiProjects 387:PrimeHunter 358:PrimeHunter 342:PrimeHunter 321:PrimeHunter 196:pseudoprime 109:Mathematics 100:mathematics 59:Mathematics 30:Start-class 424:Categories 277:MathPerson 253:number of 240:jsryork 200:Elektron 235:Jsryork 154:": --> 36:scale. 405:talk 391:talk 367:talk 346:talk 331:talk 305:talk 281:talk 156:edit 255:odd 171:not 167:all 128:??? 426:: 407:) 393:) 383:}} 380:rp 377:{{ 369:) 348:) 333:) 307:) 283:) 231:. 211:EJ 184:EJ 403:( 389:( 365:( 360:: 356:@ 344:( 329:( 323:: 319:@ 303:( 279:( 180:a 176:a 160:] 136:. 42::

Index


content assessment
WikiProjects
WikiProject icon
Mathematics
WikiProject icon
icon
Mathematics portal
WikiProject Mathematics
mathematics
the discussion
???
project's priority scale
EJ
Miller-Rabin primality test
pseudoprime
Elektron
EJ
Jsryork
12:16, 18 April 2007 (UTC)
MathPerson
talk
21:06, 30 March 2017 (UTC)
2400:C600:338A:90CB:1:0:4DE4:E106
talk
18:38, 3 May 2023 (UTC)
PrimeHunter
151.29.149.29
talk
20:09, 18 February 2024 (UTC)

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.