cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A145489 Numbers k such that 6k + 11 is prime and 12k + 5 is also prime.

Original entry on oeis.org

0, 1, 2, 3, 7, 8, 12, 16, 21, 23, 26, 37, 38, 42, 43, 47, 51, 56, 58, 63, 68, 73, 78, 91, 92, 98, 101, 106, 107, 108, 133, 136, 141, 142, 156, 157, 162, 173, 192, 196, 201, 203, 212, 218, 227, 233, 236, 238, 246, 247, 257, 267, 268, 271, 287, 296, 306, 313, 316, 323, 327, 332, 346, 353, 357, 366, 367, 371, 376, 387, 401, 406, 411, 423, 441, 442, 448, 453, 471, 472, 478, 483, 488, 491, 498
Offset: 1

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Author

Artur Jasinski, Oct 11 2008

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[0,500], PrimeQ[6# + 11 ] && PrimeQ[12# + 5]&]
  • PARI
    isok(n) = isprime(6*n+11) && isprime(12*n+5); \\ Michel Marcus, Jan 24 2017

Formula

a(n) = (A145475(n) - 5)/12.

Extensions

Corrected by Artur Jasinski, Apr 01 2011

A274465 Primes which are the sum of cousin prime pairs - 1.

Original entry on oeis.org

17, 29, 41, 89, 137, 197, 257, 389, 449, 461, 557, 617, 701, 761, 797, 881, 929, 977, 1229, 1289, 1481, 1709, 1721, 1877, 2609, 2861, 2897, 2969, 3137, 3221, 3329, 3389, 3989, 4001, 4409, 4481, 4877, 5081, 5237, 5381, 5417, 5501, 5669, 5717, 6329, 6689, 6917, 7229
Offset: 1

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Author

Keywords

Comments

Cousin primes are prime pairs that differ by 4. Any prime p in this sequence is such that p = (p-3)/2 + (p+5)/2 - 1, where (p-3)/2 and (p+5)/2 are also primes and they differ by 4.
Proper subset of A040117 (e.g., 5 isn't in the sequence). - David A. Corneth, Jun 24 2016
Intersection of A145471 and A089531. - Michel Marcus, Jun 27 2016
Subsequence of A072669. - Michel Marcus, Jun 27 2016

Examples

			17 = 7 + 11 - 1. Note that, (17-3)/2 = 7 and (17+5)/2 = 11 and 7, 11 are cousin prime pairs.
29 = 13 + 17 - 1. Note that, (29-3)/2 = 13 and (29+5)/2 = 17 and 13, 17 are cousin prime pairs.
41 = 19 + 23 - 1. Note that, (41-3)/2 = 19 and (41+5)/2 = 23 and 19, 23 are cousin prime pairs.
89 = 43 + 47 - 1. Note that, (89-3)/2 = 43 and (89+5)/2 = 47 and 43, 47 are cousin prime pairs.
		

Crossrefs

Programs

Previous Showing 21-22 of 22 results.