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A156473 Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 20. 0
2, 0, 32, 75, 3154, 31638, 4561976, 75335814, 23873894500, 748560286220, 449126699046010 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..12.

CROSSREFS

Sequence in context: A156481 A176726 A156452 * A156504 A340545 A009665

Adjacent sequences:  A156470 A156471 A156472 * A156474 A156475 A156476

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 09 2009

STATUS

approved

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Last modified June 18 22:37 EDT 2021. Contains 345125 sequences. (Running on oeis4.)