%I #7 Mar 30 2012 18:35:07
%S 0,0,0,0,0,0,0,0,0,1,3,8,20,48,112,256,576,1488,3648,8208,18239,40123,
%T 87532,189630,408376,932127,2091911,4632601,9939498,21220735,45121371,
%U 95597951,201891450
%N Number of subsets of { 1, ..., n } containing an A.P. of length 9.
%K nonn
%O 0,11
%A _David W. Wilson_