A074696 Numbers k such that 2^k+1 has more than k divisors (k such that A000005(2^k+1) > k).

0, 1, 30, 42, 45, 50, 54, 63, 70, 75, 78, 81, 90, 99, 102, 105, 114, 118, 126, 130, 135, 138, 150, 153, 154, 162, 165, 168, 170, 171, 174, 175, 177, 180, 182, 186, 189, 190, 194, 195, 196, 198, 204, 210, 216, 220, 222, 225, 228, 230, 231, 234, 238

Offset

1,3

Links

Amiram Eldar, Table of n, a(n) for n = 1..441

Mathematica

Select[Range[0, 150], DivisorSigma[0, 2^#+1] > # &] (* Amiram Eldar, May 10 2022 *)

Prog

(PARI) isok(n) = numdiv(2^n+1) > n; \\ Michel Marcus, Nov 29 2013

Crossrefs

Cf. A000005, A046798.

Sequence in context: A043900 A103098 A110849 * A378509 A127663 A008885

Adjacent sequences: A074693 A074694 A074695 * A074697 A074698 A074699

Keyword

nonn

Author

Benoit Cloitre, Sep 03 2002

Extensions

More terms from Michel Marcus, Nov 29 2013

a(1) = 0 inserted by Amiram Eldar, May 10 2022

Status

approved