A104069 Primes of the form 2^k + 31.

47, 4127, 68719476767, 3599131035634557106248430806148785487095757694641533306480604458089470064537190296255232548883112685719936728506816716098566612844395439751206812144692131084107807

Offset: 1

Author

Roger L. Bagula, Mar 02 2005

Keywords

• nonn

Comments

Associated values of k are 4, 12, 36, 540, 844, 1192, ... . - M. F. Hasler, Nov 13 2010

Crossrefs

Cf. A000040, A247952 (associated values of k).

Programs

Magma

[a: n in [0..750] | IsPrime(a) where a is 2^n+31] // Vincenzo Librandi, Nov 13 2010

Mathematica

a = Delete[Union[Flatten[Table[If [PrimeQ[2^n + 31] == True, 2^n + 31, 0], {n, 1, 400}]]], 1]

PARI

for(n=0,999, ispseudoprime(p=2^n+31) & print1(p", "))  \\ M. F. Hasler, Nov 13 2010

Formula

a(n) = 2^A247952(n) + 31. - Elmo R. Oliveira, Nov 08 2023