A284909 a(n) = A000041(A000009(n)).

1, 1, 1, 2, 2, 3, 5, 7, 11, 22, 42, 77, 176, 385, 1002, 3010, 8349, 26015, 105558, 386155, 1741630, 9289091, 49995925, 304801365, 2291320912, 18440293320, 172389800255, 1987276856363, 25025873760111, 365749566870782, 6965850144195831, 144117936527873832

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..100

Maple

with(numtheory):
b:= proc(n) option remember; `if`(n=0, 1, add(add(
     `if`(d::odd, d, 0), d=divisors(j))*b(n-j), j=1..n)/n)
    end:
a:= n-> combinat[numbpart](b(n)):
seq(a(n), n=0..35);

Mathematica

Table[PartitionsP@ PartitionsQ@ n, {n, 0, 50}] (* Indranil Ghosh, Apr 07 2017 *)

Crossrefs

Cf. A000009, A000041, A058699, A284908, A284910.

Sequence in context: A118987 A218557 A060699 * A062724 A126024 A179316

Adjacent sequences: A284906 A284907 A284908 * A284910 A284911 A284912

Keyword

nonn

Author

Alois P. Heinz, Apr 05 2017

Status

approved