A087180 - OEIS

%I #7 Feb 23 2013 04:03:56

%S 0,0,0,1,1,1,1,2,2,3,4,4,4,4,5,5,6,7,7,7,8,9,10,10,11,11,12,12,12,12,

%T 13,13,14,15,15,16,16,16,16,17,18,19,19,20,20,20,21,21,22,22,22,23,24,

%U 25,25,25,25,26,26,26,26,27,27,28,28,28,28,28,29,29,30,31,31,31,31,32

%N Number partition numbers <= P(n) of the form 3*k (P=A000041).

%C a(n) + A087181(n) + A087182(n) = n + 1.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PartitionFunction.html">Partition Function</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PartitionFunctionPCongruences.html">Partition Function P Congruences</a>

%Y Cf. A087183, A068907, A087177, A071754.

%K nonn

%O 0,8

%A _Reinhard Zumkeller_, Aug 23 2003