A074627 Numbers n such that sigma(n) is divisible by 6.

5, 6, 10, 11, 14, 15, 17, 20, 22, 23, 24, 26, 29, 30, 33, 34, 35, 38, 40, 41, 42, 44, 45, 46, 47, 51, 53, 54, 55, 56, 58, 59, 60, 62, 65, 66, 68, 69, 70, 71, 74, 77, 78, 80, 82, 83, 85, 86, 87, 88, 89, 90, 92, 94, 95, 96, 99, 101, 102, 104, 105, 106, 107, 110, 113, 114, 115

Offset

1,1

Comments

n=10: sigma(10) = 1+2+5+10 = 18 = 3*6.

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Formula

A000203(n) modulo 6 = 0.

{n: A084301(n) = 0 }. - R. J. Mathar, May 19 2020

A087943 INTERSECT A028983. - R. J. Mathar, May 19 2020

Mathematica

Select[Range@ 120, Divisible[DivisorSigma[1, #], 6] &] (* Michael De Vlieger, Feb 25 2017 *)

Prog

(PARI) isok(n) = !(sigma(n) % 6); \\ Michel Marcus, Dec 17 2013

Crossrefs

Cf. A000203, A072862, A074384, A074628, A067051, A074630.

Sequence in context: A042958 A265188 A163903 * A067612 A374492 A064957

Adjacent sequences: A074624 A074625 A074626 * A074628 A074629 A074630

Keyword

easy,nonn

Author

Labos Elemer, Aug 26 2002

Status

approved