A156514 Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 51.

5, 116, 452, 60568, 662388, 382580208, 13757627936, 22555562198752

Offset

3,1

Links

Table of n, a(n) for n=3..10.

Crossrefs

Sequence in context: A245105 A080988 A230338 * A319392 A268606 A006221

Adjacent sequences: A156511 A156512 A156513 * A156515 A156516 A156517

Keyword

nonn

Author

R. H. Hardin Feb 09 2009

Status

approved