%I #4 Dec 18 2015 18:18:12
%S 3,148,40370,56599992,361204218672
%N Number of n X n 0..7 matrices whose square is also a 0..7 matrix
%C Column 7 of A213990
%e Some.solutions.for.n=3
%e ..0..1..7....0..5..3....0..2..1....0..1..7....0..2..5....2..0..0....0..7..0
%e ..0..0..5....0..0..0....0..0..0....0..0..2....0..0..0....0..1..1....0..1..0
%e ..0..0..0....0..0..0....0..3..2....0..0..0....0..0..1....0..0..1....0..6..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Jun 30 2012
