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

2,2

Links

Table of n, a(n) for n=2..25.

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

Crossrefs

Sequence in context: A214181 A275653 A214232 * A301651 A159379 A323571

Adjacent sequences: A146194 A146195 A146196 * A146198 A146199 A146200

Keyword

nonn

Author

R. H. Hardin Apr 14 2009

Status

approved