A139234 First differences of even superperfect numbers A061652.

2, 12, 48, 4032, 61440, 196608, 1073479680, 1152921503533105152, 309485008668423564117934080, 81129328929596860350720280363008, 85070510600596201259161956068936908800

Offset: 1

Author

Omar E. Pol, Apr 18 2008

Keywords

• nonn

Comments

First differences of Mersenne primes A000668, divided by 2 (see A139231).

Also, first differences of superperfect numbers A019279, if there are no odd superperfect numbers.

Examples

			a(2) = 12 because A061652(2) = 4 and A061652(3) = 16 then 16 - 4 = 12.
		

Crossrefs

Cf. A000668, A019279, A061652, A139228, A139229, A139230, A139231, A139232, A139233, A139235, A139236, A139237.

Programs

Mathematica

Differences[Table[2^(MersennePrimeExponent[n]-1),{n,12}]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 18 2020 *)

Formula

a(n) = A061652(n+1) - A061652(n) = A139231(n)/2. Also, a(n) = A019279(n+1) - A019279(n), if there are no odd superperfect numbers.

Extensions

a(8)-a(11) from A139231(n)/2 by Jinyuan Wang, Mar 04 2020