%I A011874
%S A011874 0,0,0,0,0,0,1,2,2,3,4,5,6,7,8,10,11,12,14,16,18,20,22,
%T A011874 24,26,28,30,33,36,38,41,44,47,50,53,56,60,63,66,70,74,
%U A011874 78,82,86,90,94,98,102,107,112,116,121,126,131,136,141
%N A011874 [ n(n-1)/21 ].
%F A011874 G.f.: x^6(1-x^2+x^3+x^9-x^10+x^12)/((1-x)^2*(1-x^21)). [From R. J. Mathar 
               (mathar(AT)strw.leidenuniv.nl), Sep 09 2008]
%Y A011874 Sequence in context: A017896 A118868 A017885 this_sequence A000115 A033552 
               A062420
%Y A011874 Adjacent sequences: A011871 A011872 A011873 this_sequence A011875 A011876 
               A011877
%K A011874 nonn
%O A011874 0,8
%A A011874 N. J. A. Sloane (njas(AT)research.att.com).