A139243 Second differences of Mersenne numbers A001348, divided by 4.

5, 18, 456, 1056, 29184, 67584, 1867776, 130154496, 270532608, 33420214272, 481573208064, 1133871366144, 31336081391616, 2183630092763136, 139646772820574208, 290482175965396992, 35884681830888112128, 517085294816170868736, 1217485108864830406656

Offset: 1

Author

Omar E. Pol, Apr 19 2008

Keywords

• easy
• nonn

Links

• Paolo Xausa, Table of n, a(n) for n = 1..450

Crossrefs

Cf. A001348, A139237, A139239, A139240, A139241, A139242.

Programs

Mathematica

Differences[2^Prime[Range[25]]-1,2]/4 (* Paolo Xausa, Oct 20 2023 *)

Formula

a(n) = A139241(n)/4 = A139242(n)/2.

Extensions

More terms from Alois P. Heinz, Mar 13 2020