A139237 Second differences of even superperfect numbers A061652, divided by 2.

5, 18, 1992, 28704, 67584, 536641536, 576460751229812736, 154742503757751030292414464, 40564509722294095963578081214464, 42535214735633635831150802674328272896

Offset: 1

Author

Omar E. Pol, Apr 18 2008

Keywords

• nonn

Comments

Second differences of Mersenne primes A000668, divided by 4 (see A139232).

Also, second differences of superperfect numbers A019279, divided by 2, if there are no odd superperfect numbers.

Links

• Paolo Xausa, Table of n, a(n) for n = 1..16

Crossrefs

Cf. A000668, A019279, A061652, A139228, A139229, A139230, A139231, A139232, A139233, A139234, A139235, A139236.

Programs

Mathematica

Differences[2^MersennePrimeExponent[Range[14]]-1,2]/4 (* Paolo Xausa, Oct 20 2023 *)

Formula

a(n) = A139236(n)/2.

Extensions

More terms from Michel Marcus, Jul 09 2017