A156506 Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 41.

2, 4, 108, 194, 11736, 89724, 68108540, 1149707144, 4558233650072

Offset

2,1

Links

Table of n, a(n) for n=2..10.

Crossrefs

Sequence in context: A000965 A266176 A018449 * A018455 A264648 A289343

Adjacent sequences: A156503 A156504 A156505 * A156507 A156508 A156509

Keyword

nonn

Author

R. H. Hardin, Feb 09 2009

Status

approved