%I

%S 6,130,1872,121382,17647254,18669753424,68782403549580,

%T 503051985491086584

%N Number of n X n arrays of squares of integers, symmetric about main diagonal, with all rows summing to 21.

%K nonn

%O 3,1

%A _R. H. Hardin_ Feb 09 2009