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

1,9

Links

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

Formula

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

Prog

(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));

Crossrefs

Cf. A001055, A349906.

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

Sequence in context: A341514 A276084 A230403 * A248908 A133565 A239704

Adjacent sequences: A349904 A349905 A349906 * A349908 A349909 A349910

Keyword

nonn

Author

Antti Karttunen, Dec 13 2021

Status

approved