A258596 Number of divisors of the number of partitions of n into distinct parts, a(n) = A000005(A000009(n)).

1, 1, 1, 2, 2, 2, 3, 2, 4, 4, 4, 6, 4, 6, 4, 4, 6, 4, 4, 8, 7, 6, 2, 8, 4, 4, 8, 14, 8, 9, 8, 12, 16, 14, 10, 12, 6, 16, 24, 4, 8, 36, 8, 16, 8, 12, 27, 16, 16, 28, 8, 4, 8, 22, 8, 8, 6, 16, 16, 42, 32, 6, 8, 20, 6, 48, 12, 16, 28, 8, 2, 12, 20, 16, 12, 4, 32

Offset

0,4

Comments

a(n) is odd for n = 0, 1, 2, 6, 20, 29, 46, ... ; see A035142. - Michel Marcus, Jun 19 2015

Links

Giovanni Resta, Table of n, a(n) for n = 0..10000

Formula

a(n) = A000005(A000009(n)).

Mathematica

DivisorSigma[0, PartitionsQ@ Range[0, 100]]

Prog

(PARI) a(n) = numdiv(polcoeff(prod(k=1, n, 1 + x^k, 1 + x * O(x^n)), n)); \\ Michel Marcus, Jun 19 2015

Crossrefs

Cf. A000009, A085543.

Sequence in context: A329434 A157231 A332888 * A273784 A318058 A345901

Adjacent sequences: A258593 A258594 A258595 * A258597 A258598 A258599

Keyword

nonn

Author

Giovanni Resta, Jun 04 2015

Status

approved