A156472 Number of n X n arrays of squares of integers, symmetric about main diagonal, with all rows summing to 20.

2, 6, 60, 1239, 112892, 47944020, 53004021504, 118418512901454, 524860935683590152

Offset

2,1

Links

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

Crossrefs

Sequence in context: A089039 A156451 A152617 * A108640 A084971 A224883

Adjacent sequences: A156469 A156470 A156471 * A156473 A156474 A156475

Keyword

nonn

Author

R. H. Hardin Feb 09 2009

Status

approved