A146197 Number of n X n arrays of squares of integers summing to 6 with every element equal to at least one neighbor.

0, 18, 1070, 8266, 33102, 97050, 236458, 508330, 997046, 1822042, 3146450, 5186698, 8223070, 12611226, 18794682, 27318250, 38842438, 54158810, 74206306, 100088522, 133091950, 174705178, 226639050, 290847786

Offset: 2

Author

R. H. Hardin Apr 14 2009

Keywords

• nonn

Formula

Empirical (for n>=5): a(n) = 4*n^6/3 - 4*n^5 + 14*n^4 - 178*n^3/3 - 886*n^2/3 + 3958*n/3 - 614. - Vaclav Kotesovec, Nov 30 2012