A156475 Number of n X n arrays of squares of integers, symmetric about main diagonal, with all rows summing to 21.

6, 130, 1872, 121382, 17647254, 18669753424, 68782403549580, 503051985491086584

Offset

3,1

Links

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

Crossrefs

Sequence in context: A338709 A318528 A095695 * A000907 A188718 A077031

Adjacent sequences: A156472 A156473 A156474 * A156476 A156477 A156478

Keyword

nonn

Author

R. H. Hardin Feb 09 2009

Status

approved