A139287 2^(2p - 1) - 1, where p is prime.

7, 31, 511, 8191, 2097151, 33554431, 8589934591, 137438953471, 35184372088831, 144115188075855871, 2305843009213693951, 9444732965739290427391, 2417851639229258349412351, 38685626227668133590597631

Offset: 1

Author

Omar E. Pol, Apr 13 2008

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A000040, A000079, A076274, A139286, A139288, A139289, A139290, A139291, A139292, A139293, A139294, A139306.

Programs

Magma

[2^(2*p-1)-1: p in PrimesUpTo(200)]; // Vincenzo Librandi, Dec 15 2010

Mathematica

Table[(2^(2 Prime[n] - 1) - 1), {n, 1, 20}] (* Vincenzo Librandi, May 24 2014 *)

Extensions

a(9) corrected by Vincenzo Librandi, May 24 2014