A349907 Number of factorizations of n into odd factors > 1 (a(1) = 1 by convention).

1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 2, 0, 1, 0, 2, 0, 3, 0, 1, 0, 1, 0, 2, 0, 2, 0, 1, 0, 2, 0, 1, 0, 1, 0, 4, 0, 1, 0, 2, 0, 2, 0, 1, 0, 2, 0, 2, 0, 1, 0, 1, 0, 4, 0, 2, 0, 1, 0, 2, 0, 1, 0, 1, 0, 4, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 2, 0, 1, 0, 2, 0, 2, 0, 2, 0, 1, 0, 4, 0, 1, 0, 1, 0, 5

Offset: 1

Author

Antti Karttunen, Dec 13 2021

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A001055, A349906.

Cf. A000004, A340101 (even and odd bisections).

Programs

PARI

A349907(n, m=n) = if(1==n, 1, my(s=0); fordiv(n, d, if((d>1)&&(d<=m)&&(d%2), s += A349907(n/d, d))); (s));

Formula

a(2n) = 0, a(2n-1) = A001055(2n-1).