A156441 Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 6.

2, 22, 32, 635, 1414, 32990, 130456, 4220548, 36058540, 1814137996, 26532092944, 1840450801838, 35263399597916, 3086652618464548, 71091010320744928, 7527949573364777296

Offset

3,1

Links

Table of n, a(n) for n=3..18.

Crossrefs

Sequence in context: A085185 A166726 A373054 * A094625 A130751 A227534

Adjacent sequences: A156438 A156439 A156440 * A156442 A156443 A156444

Keyword

nonn

Author

R. H. Hardin Feb 09 2009

Status

approved