A344974 Numbers k such that A011772(k) divides A344875(k).

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 16, 17, 18, 19, 21, 23, 24, 25, 26, 27, 28, 29, 31, 32, 34, 36, 37, 39, 40, 41, 43, 47, 49, 50, 53, 55, 57, 58, 59, 61, 64, 67, 68, 71, 73, 74, 75, 78, 79, 81, 82, 83, 89, 93, 96, 97, 98, 100, 101, 103, 106, 107, 109, 111, 113, 120, 121, 122, 125, 127, 128, 129, 131, 136, 137

Offset: 1

Author

Antti Karttunen, Jun 04 2021

Keywords

• nonn

Crossrefs

Cf. A011772, A344875, A344884 (characteristic function).

Positions of ones in A344970, of zeros in A344973.

Union of A000961 and A344975. Complement of A344980.

Cf. also A344595 (subsequence).

Programs

Mathematica

A011772[n_] := Module[{m = 1}, While[Not[IntegerQ[m(m+1)/(2n)]], m++]; m];
A344875[n_] := Product[{p, e} = pe; If[p == 2, 2^(1+e)-1, p^e-1], {pe, FactorInteger[n]}];
Select[Range[200], Divisible[A344875[#], A011772[#]]&] (* Jean-François Alcover, Jun 12 2021 *)

PARI

isA344974(n) = (0==A344973(n));