A156473 Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 20.

2, 0, 32, 75, 3154, 31638, 4561976, 75335814, 23873894500, 748560286220, 449126699046010

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