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A159357
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Number of n X n arrays of squares of integers with every (n-2)X(n-2) subblock summing to 4
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1
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13, 3223, 120420, 1313859, 7979037, 34212213, 116257928, 334277285, 847224269, 1945263907, 4124812588, 8191927383, 15400417725, 27631699329, 47624056752, 79259627513, 127918067213, 200906501615, 307976018164, 461935595947
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OFFSET
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4,1
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LINKS
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FORMULA
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Empirical G.f.: -17*x^3 - x^3*(17 - 140*x + 3718*x^2 + 90453*x^3 + 347157*x^4 + 218190*x^5 - 9588*x^6 - 3511*x^7 + 224*x^8)/(-1+x)^9. - Vaclav Kotesovec, Nov 30 2012
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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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