A078118 n+1 does not divide sigma(n!).

1, 6, 22, 25, 28, 30, 40, 42, 46, 52, 58, 60, 68, 70, 72, 78, 87, 88, 96, 98, 102, 105, 106, 112, 114, 122, 126, 128, 130, 133, 138, 145, 148, 150, 156, 162, 166, 172, 178, 182, 190, 192, 196, 198, 212, 213, 217, 218, 222, 225, 226, 228, 232, 238, 240, 250, 262

Offset

1,2

Links

Vaclav Kotesovec, Table of n, a(n) for n = 1..8822

Vaclav Kotesovec, Plot of a(n)/n for n = 1..8000

Formula

a(n) seems to be asymptotic to c*n with c=4.8....

Mathematica

Select[Range[300], Not[Divisible[DivisorSigma[1, #!], # + 1]] &] (* Vaclav Kotesovec, Feb 16 2019 *)

Crossrefs

Cf. A062569.

Sequence in context: A055043 A044067 A106685 * A095411 A242592 A044448

Adjacent sequences: A078115 A078116 A078117 * A078119 A078120 A078121

Keyword

nonn

Author

Benoit Cloitre, Dec 05 2002

Status

approved