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Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 9.
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%I #4 Dec 18 2015 18:17:16

%S 1,2,4,28,68,788,2096,74764,297215,56568904,378230514,110049447136,

%T 1117730631388,399699792848864,6285859127170900,2788382742936560544

%N Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 9.

%K nonn

%O 1,2

%A _R. H. Hardin_ Feb 09 2009