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%I #18 Apr 06 2017 13:06:54
%S 1,1,2,3,7,15,56,176,1002,5604,53174,526823,10619863,214481126,
%T 9035836076,476715857290,51820051838712,7479565078510584,
%U 2645418340688763701,1318520401612270233223,1774758704783877366657989,4025091510519029370421431033
%N a(n) = p(p(n)), p = partition numbers A000041.
%H Alois P. Heinz, <a href="/A058699/b058699.txt">Table of n, a(n) for n = 0..50</a>
%F a(n) = A000041(A000041(n)). - _Omar E. Pol_, Apr 25 2016
%p a:= n-> (combinat[numbpart]@@2)(n):
%p seq(a(n), n=0..22); # _Alois P. Heinz_, Apr 05 2017
%t Table[Nest[PartitionsP, n, 2], {n, 0, 20}] (* _Michael De Vlieger_, Apr 25 2016 *)
%o (PARI) a(n) = numbpart(numbpart(n)); \\ _Michel Marcus_, Apr 25 2016
%Y Cf. A000009, A000041, A284908, A284909, A284910.
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Dec 31 2000
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