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

1,2

Links

Table of n, a(n) for n=1..77.

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 *)

Prog

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

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).

Sequence in context: A344452 A101373 A371421 * A371022 A107062 A178538

Adjacent sequences: A344971 A344972 A344973 * A344975 A344976 A344977

Keyword

nonn

Author

Antti Karttunen, Jun 04 2021

Status

approved