A272209 - OEIS

%I #17 May 25 2017 10:01:39

%S 1,2,2,3,2,5,2,5,3,5,2,11,2,5,5,7,2,11,2,11,5,5,2,22,3,5,5,11,2,22,2,

%T 11,5,5,5,30,2,5,5,22,2,22,2,11,11,5,2,42,3,11,5,11,2,22,5,22,5,5,2,

%U 77,2,5,11,15,5,22,2,11,5,22,2,77,2,5,11,11,5,22,2,42,7,5,2,77

%N Number of partitions of the number of divisors of n.

%H Antti Karttunen, <a href="/A272209/b272209.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = p(d(n)) = A000041(A000005(n)).

%e For n = 12 the divisors of 12 are 1, 2, 3, 4, 6, 12. There are 6 divisors of 12 and the number of partitions of 6 is A000041(6) = 11, so a(12) = 11.

%t Table[PartitionsP@ DivisorSigma[0, n], {n, 120}] (* _Michael De Vlieger_, Apr 25 2016 *)

%o (PARI) a(n) = numbpart(numdiv(n)); \\ _Michel Marcus_, Apr 26 2016

%Y Cf. A000005, A000041, A035116, A058699, A085543, A272024.

%K nonn

%O 1,2

%A _Omar E. Pol_, Apr 25 2016