A023331 Primes that remain prime through 5 iterations of function f(x) = 2x + 3.

47, 67, 1427, 6047, 12097, 16057, 44507, 76537, 92387, 100057, 132707, 209647, 263387, 354247, 407947, 465407, 477727, 507757, 775237, 787477, 788687, 865327, 907367, 955457, 1015517, 1121387, 1178197, 1302277, 1360367, 1524247, 1623707

Offset

1,1

Comments

Primes p such that 2*p+3, 4*p+9, 8*p+21, 16*p+45 and 32*p+93 are also prime. - Vincenzo Librandi, Aug 04 2010

Subsequence of A023303. - Michel Marcus, Jun 25 2014

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..148

Mathematica

Select[Prime[Range[20000]], And@@PrimeQ[NestList[2 # + 3 &, #, 5]] &] (* Vincenzo Librandi, Jun 25 2014 *)

Prog

(Magma) [p: p in PrimesUpTo(2000000) | IsPrime(2*p+3) and IsPrime(4*p+9) and IsPrime(8*p+21) and IsPrime(16*p+45) and IsPrime(32*p+93)]; // Vincenzo Librandi, Aug 04 2010

Crossrefs

Cf. A023303 (through 4 iterations).

Sequence in context: A348421 A106874 A245745 * A187923 A103012 A166958

Adjacent sequences: A023328 A023329 A023330 * A023332 A023333 A023334

Keyword

nonn

Author

David W. Wilson

Status

approved