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A156469
Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 18.
0
1, 4, 54, 112, 5414, 21624, 2133044, 23029656, 5468265896, 163052061000, 97305384072800
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OFFSET
2,2
LINKS
Table of n, a(n) for n=2..12.
CROSSREFS
Sequence in context:
A158259
A362050
A095210
*
A001545
A208954
A384703
Adjacent sequences:
A156466
A156467
A156468
*
A156470
A156471
A156472
KEYWORD
nonn
AUTHOR
R. H. Hardin
, Feb 09 2009
STATUS
approved
