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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.
1
0, 40, 5606, 41698, 158360, 453388, 1097036, 2364072, 4672136, 8626500, 15071228, 25146736, 40353752, 62623676, 94395340, 138698168, 199241736, 280511732, 387872316, 527674880, 707373208
OFFSET
3,2
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
CROSSREFS
Sequence in context: A270053 A123810 A275655 * A159376 A364507 A196706
KEYWORD
nonn
AUTHOR
R. H. Hardin Apr 14 2009
STATUS
approved