A065869 a(n) = (2^(prime(n)^2) + 1)/(2^prime(n) + 1).

57, 1016801, 4363953127297, 1297440698667560637290197228189697, 91332703321545501540374299322682400349546864641, 7588492464653843921408409789152927606760448769729047438304822150910706202078740481

Offset: 2

Author

Benoit Cloitre, Dec 07 2001

Keywords

• nonn

Links

• Harry J. Smith, Table of n, a(n) for n = 2..16

Crossrefs

Cf. A051156, A069255.

Programs

Mathematica

(2^#^2+1)/(2^#+1)&/@Prime[Range[2,10]] (* Harvey P. Dale, May 09 2025 *)

PARI

a(n) = { (2^(prime(n)^2) + 1)/(2^prime(n) + 1) } \\ Harry J. Smith, Nov 02 2009

Formula

a(n) = A069255((prime(n)+1)/2). - Andrew Howroyd, Dec 09 2024