%I #3 Mar 31 2012 12:35:07
%S 1,2,8,61,957,31520,2199080,328002710,105370907181
%N Number of n X n symmetric matrices with nonnegative integer entries with each row sum i equal to i (1..n).
%K nonn
%O 1,2
%A _R. H. Hardin_, Jul 12 2008