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A146126
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Number of n X n arrays of squares of integers with every (n-2) X (n-2) subblock summing to 5 and every element equal to at least one neighbor.
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1
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0, 235, 9716, 43201, 125064, 290427, 583948, 1060251, 1783944, 2829619, 4281852, 6235203, 8794216, 12073419, 16197324, 21300427, 27527208, 35032131, 43979644, 54544179, 66910152
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OFFSET
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4,2
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LINKS
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FORMULA
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Empirical (for n>=8): a(n) = 416*n^4 - 6704*n^3 + 42495*n^2 - 127724*n + 155688. - Vaclav Kotesovec, Nov 30 2012
G.f.: x^5*(235 + 8541*x - 3029*x^2 + 3869*x^3 + 1132*x^4 - 1212*x^5 + 430*x^6 + 18*x^7) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>12.
(End)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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