A023332 Primes that remain prime through 5 iterations of function f(x) = 2x + 5.

13, 541, 1087, 1861, 3727, 23293, 40387, 87643, 98899, 109111, 115153, 116329, 119101, 131617, 133597, 163909, 197521, 214021, 215389, 218227, 238207, 263239, 294751, 489901, 493693, 665527, 734131, 767881, 808693, 895351, 1038127, 1051957

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 2*p+5, 4*p+15, 8*p+35, 16*p+75 and 32*p+155 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

• John Cerkan, Table of n, a(n) for n = 1..10000

Crossrefs

Subsequence of A023205, A023243, A023274, A023304, and A089038.

Programs

Magma

[n: n in [1..5000000] | IsPrime(n) and IsPrime(2*n+5) and IsPrime(4*n+15) and IsPrime(8*n+35) and IsPrime(16*n+75) and IsPrime(32*n+155)] // Vincenzo Librandi, Aug 04 2010

Mathematica

txQ[p_]:=AllTrue[NestList[2#+5&,p,5],PrimeQ]; Select[Prime[Range[83000]],txQ] (* Harvey P. Dale, May 10 2024 *)

Formula

a(n) == 1 (mod 6). - John Cerkan, Oct 09 2016