A112277 Numbers m such that A112276(m) is composite.

8, 14, 20, 21, 24, 26, 32, 33, 34, 38, 44, 45, 48, 50, 54, 55, 56, 57, 62, 63, 64, 68, 74, 75, 76, 80, 81, 84, 85, 86, 90, 91, 92, 93, 94, 98, 104, 105, 110, 114, 115, 116, 117, 118, 119, 120, 122, 123, 124, 128, 132, 133, 135, 140, 141, 142, 143, 144, 145, 147, 152

Offset: 1

Author

Reinhard Zumkeller, Sep 01 2005

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000005, A066247, A112276.

Programs

Mathematica

f[1] = 1; f[n_] := Module[{m = n + 1, d = DivisorSigma[0, n]}, While[DivisorSigma[0, m] > d, m++]; m]; Select[Range[150], CompositeQ[f[#]] &] (* Amiram Eldar, Feb 03 2020 *)

Formula

A000005(a(n)) <= A000005(A112276(a(n))).

A066247(A112276(a(n))) = 1.