A134713 Base-2 logarithm of (n-th even superperfect number divided by 2^n), plus 1.

1, 1, 2, 3, 8, 11, 12, 23, 52, 79, 96, 115, 508, 593, 1264, 2187, 2264, 3199, 4234, 4403, 9668, 9919, 11190, 19913, 21676, 23183, 44470, 86215, 110474, 132019, 216060, 756807, 859400, 1257753, 1398234, 2976185, 3021340, 6972555, 13466878

Offset

1,3

Links

Amiram Eldar, Table of n, a(n) for n = 1..48

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.

Formula

a(n) = 1 + log_2(A061652(n)/(2^n)) = A000043(n) - n = A090748(n) - n + 1.

Example

a(5) = 8 because the 5th even superperfect number is 4096, 2^5 = 32, 4096/32 = 128, log_2(128) = 7 (because 2^7 = 128) and 7+1 = 8.

Mathematica

With[{max = 48}, MersennePrimeExponent[Range[max]] - Range[max]] (* Amiram Eldar, Oct 21 2024 *)

Crossrefs

Cf. A000043, A000396, A000668, A019279, A061652, A090748, A133028.

Sequence in context: A118089 A201541 A084917 * A293910 A173269 A364217

Adjacent sequences: A134710 A134711 A134712 * A134714 A134715 A134716

Keyword

nonn

Author

Omar E. Pol, Nov 07 2007

Status

approved