A139481 a(n) = A139480(n)/2.

0, 1, 2, 5, 7, 8, 14, 29, 43, 52, 62, 259, 302, 638, 1100, 1139, 1607, 2125, 2210, 4843, 4969, 5605, 9967, 10849, 11603, 22247, 43120, 55250, 66023, 108044, 378418, 429715, 628892, 699133, 1488109, 1510687, 3486295, 6733457, 10498004, 12018290

Offset: 2

Author

Artur Jasinski, Apr 22 2008

Keywords

• nonn
• less

Links

• Amiram Eldar, Table of n, a(n) for n = 2..48

Crossrefs

Cf. A000043, A000668, A124477, A139479, A139480, A146768.

Programs

Mathematica

(MersennePrimeExponent[Range[2, 48]] - 3)/2 (* Amiram Eldar, Oct 17 2024 *)

Formula

a(n) = A146768(n-1)-1. - R. J. Mathar, Mar 30 2011

Extensions

Edited by N. J. A. Sloane, May 23 2008