A156523 Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 68.

2, 2, 80, 404, 63392, 1572582, 1619260788, 75946691122

Offset

2,1

Links

Table of n, a(n) for n=2..9.

Crossrefs

Sequence in context: A370736 A230054 A303569 * A191779 A156511 A166996

Adjacent sequences: A156520 A156521 A156522 * A156524 A156525 A156526

Keyword

nonn

Author

R. H. Hardin Feb 09 2009

Status

approved