A156458 Number of n X n arrays of squares of integers, symmetric about main diagonal, with all rows summing to 13.

2, 6, 68, 876, 43300, 3026820, 558858552, 474109634808, 1011861877473980, 3520221010293816000

Offset

2,1

Links

Table of n, a(n) for n=2..11.

Crossrefs

Sequence in context: A087331 A097419 A219037 * A244494 A136268 A030242

Adjacent sequences: A156455 A156456 A156457 * A156459 A156460 A156461

Keyword

nonn

Author

R. H. Hardin Feb 09 2009

Status

approved