A146198 Number of n X n arrays of squares of integers with every (n-1)X(n-1) subblock summing to 6 and every element equal to at least one neighbor.

0, 40, 5606, 41698, 158360, 453388, 1097036, 2364072, 4672136, 8626500, 15071228, 25146736, 40353752, 62623676, 94395340, 138698168, 199241736, 280511732, 387872316, 527674880, 707373208

Offset: 3

Author

R. H. Hardin Apr 14 2009

Keywords

• nonn

Formula

Empirical (for n>=7): a(n) = 80*n^6/9 - 401*n^5/3 + 10112*n^4/9 - 5809*n^3 + 145814*n^2/9 - 64942*n/3 + 11612. - Vaclav Kotesovec, Nov 30 2012