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A156442
Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 6.
0
2, 0, 7, 0, 870, 0, 68180, 0, 18391220, 0, 10399874310, 0, 10075020851140, 0, 14707103186511120, 0
OFFSET
4,1
CROSSREFS
Sequence in context: A266220 A022897 A192496 * A268683 A174968 A254445
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 09 2009
STATUS
approved