%I A156436
%S A156436 1,0,0,3,5,12,54,426,2334,23280,152820,1939740,14564760,222925920,
%T A156436 1890254100,33899743010,320743643010,6597891367200,68944295861280,
%U A156436 1600434039456630,18309730315533930,473501454337711800
%N A156436 Number of nXn arrays of squares of integers, symmetric under 90 degree 
               rotation, with all rows summing to 4.
%Y A156436 Sequence in context: A046091 A002905 A087610 this_sequence A099791 A028268 
               A137162
%Y A156436 Adjacent sequences: A156433 A156434 A156435 this_sequence A156437 A156438 
               A156439
%K A156436 nonn
%O A156436 1,4
%A A156436 Ron Hardin (rhhardin(AT)att.net) Feb 09 2009