A023306 Primes that remain prime through 4 iterations of function f(x) = 2x + 9.

11, 31, 1181, 2521, 3701, 4211, 4931, 8221, 8461, 9871, 11981, 13121, 14591, 16381, 16901, 21991, 23021, 34961, 36781, 37691, 43991, 44531, 45181, 46021, 46051, 52321, 57601, 59921, 62081, 75391, 89071, 92051, 95621, 105361, 115211, 124171, 128461

Offset

1,1

Comments

Primes p such that 2*p+9, 4*p+27, 8*p+63 and 16*p+135 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

Select[Prime[Range[12500]], And@@PrimeQ[Rest[NestList[2#+9&, #, 4]]]&] (* Harvey P. Dale, Jan 01 2014 *)

Prog

(Magma) [n: n in [1..1000000] | IsPrime(n) and IsPrime(2*n+9) and IsPrime(4*n+27) and IsPrime(8*n+63) and IsPrime(16*n+135)] // Vincenzo Librandi, Aug 04 2010

Crossrefs

Sequence in context: A201808 A111015 A143765 * A068839 A228530 A177360

Adjacent sequences: A023303 A023304 A023305 * A023307 A023308 A023309

Keyword

nonn

Author

David W. Wilson

Status

approved