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A156428
Number of 20 X 20 arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to n.
0
1, 921184, 52745205240, 367381371180384, 514918876680042334, 195842622547532763968
OFFSET
0,2
CROSSREFS
Sequence in context: A185532 A360907 A321323 * A251954 A098208 A251172
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 09 2009
STATUS
approved