A023344 Primes that remain prime through 5 iterations of function f(x) = 5x + 8.

7, 7621, 15937, 382933, 462271, 518803, 866941, 1025407, 1142503, 1427347, 1742473, 1980067, 2343619, 2910031, 3015283, 4344121, 4352269, 4544209, 5081893, 5116543, 5127043, 5482531, 5484379, 5501473, 5648221, 6452899, 7213897, 7968469

Offset

1,1

Comments

Primes p such that 5*p+8, 25*p+48, 125*p+248, 625*p+1248 and 3125*p+6248 are also primes. - Vincenzo Librandi, Aug 05 2010

Links

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

Formula

a(n) == 19 (mod 42) for n > 1. - John Cerkan, Oct 22 2016

Mathematica

Select[Prime[Range[550000]], And@@PrimeQ[NestList[5#+8&, #, 5]]&] (* Harvey P. Dale, Jun 04 2011 *)

Prog

(Magma) [n: n in [1..10000000] | IsPrime(n) and IsPrime(5*n+8) and IsPrime(25*n+48) and IsPrime(125*n+248) and IsPrime(625*n+1248) and IsPrime(3125*n+6248)] // Vincenzo Librandi, Aug 05 2010

Crossrefs

Subsequence of A023220, A023255, A023286, A023316, and A111225.

Sequence in context: A119528 A116266 A179812 * A297050 A137693 A247822

Adjacent sequences: A023341 A023342 A023343 * A023345 A023346 A023347

Keyword

nonn

Author

David W. Wilson

Status

approved