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

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

Offset

1,1

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

Formula

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

Mathematica

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

Crossrefs

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

Sequence in context: A359560 A139243 A347670 * A317541 A342175 A258080

Adjacent sequences: A139234 A139235 A139236 * A139238 A139239 A139240

Keyword

nonn

Author

Omar E. Pol, Apr 18 2008

Extensions

More terms from Michel Marcus, Jul 09 2017

Status

approved