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A156450
Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 9.
0
1, 0, 0, 4, 4, 0, 0, 1836, 6871, 0, 0, 294400160, 3360660500, 0, 0, 2033591738777760, 62993444371397120, 0
OFFSET
1,4
CROSSREFS
Sequence in context: A260318 A075866 A202168 * A067007 A066298 A108068
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 09 2009
STATUS
approved