login
a(n) = A000009(A000009(n)).
5

%I #11 Apr 07 2017 01:36:04

%S 1,1,1,1,1,2,2,3,4,6,10,15,27,46,89,192,390,864,2304,5718,16444,53250,

%T 173682,618784,2556284,11086968,53466624,299016608,1780751883,

%U 11784471548,94036004868,795888123110,7723778471936,91117574462854,1168225267521350

%N a(n) = A000009(A000009(n)).

%H Alois P. Heinz, <a href="/A284908/b284908.txt">Table of n, a(n) for n = 0..70</a>

%p with(numtheory):

%p b:= proc(n) option remember; `if`(n=0, 1, add(add(

%p `if`(d::odd, d, 0), d=divisors(j))*b(n-j), j=1..n)/n)

%p end:

%p a:= n-> b(b(n)):

%p seq(a(n), n=0..35);

%t Table[PartitionsQ@ PartitionsQ@ n, {n, 0, 50}] (* _Indranil Ghosh_, Apr 07 2017 *)

%Y Cf. A000009, A000041, A058699, A284909, A284910.

%K nonn

%O 0,6

%A _Alois P. Heinz_, Apr 05 2017