A097503 Numbers k such that A000203(k) = sigma(k) is not divisible by 6.

1, 2, 3, 4, 7, 8, 9, 12, 13, 16, 18, 19, 21, 25, 27, 28, 31, 32, 36, 37, 39, 43, 48, 49, 50, 52, 57, 61, 63, 64, 67, 72, 73, 75, 76, 79, 81, 84, 91, 93, 97, 98, 100, 103, 108, 109, 111, 112, 117, 121, 124, 127, 128, 129, 133, 139, 144, 148, 151, 156, 157, 162, 163, 169

Offset

1,2

Comments

Positions of nonzero terms in A084301. - Ivan Neretin, Jan 26 2017

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[170], ! Divisible[DivisorSigma[1, #], 6] &] (* Ivan Neretin, Jan 26 2017 *)

Prog

(PARI) isok(n) = (sigma(n) % 6) != 0; \\ Michel Marcus, Jan 26 2017

Crossrefs

Cf. A000203, A084301.

Complement of A074627.

Sequence in context: A276876 A047202 A064953 * A030701 A305924 A328134

Adjacent sequences: A097500 A097501 A097502 * A097504 A097505 A097506

Keyword

nonn

Author

Labos Elemer, Aug 23 2004

Extensions

Definition corrected by Ivan Neretin, Jan 26 2017

Status

approved