A156429 Number of 20 X 20 arrays of squares of integers, symmetric under 90-degree rotation, with all rows summing to n.

1, 30240, 569744280, 1972495637280, 1600434039456630, 374736233227188672

Offset

0,2

Links

Table of n, a(n) for n=0..5.

Crossrefs

Sequence in context: A218029 A323991 A109485 * A171263 A233731 A187376

Adjacent sequences: A156426 A156427 A156428 * A156430 A156431 A156432

Keyword

nonn

Author

R. H. Hardin, Feb 09 2009

Status

approved