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A183645
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Number of (n+1) X 3 0..4 arrays with every 2 X 2 subblock summing to 8.
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1
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325, 1001, 3445, 12785, 50125, 205001, 867205, 3771425, 16784125, 76156601, 351254965, 1642635665, 7771818925, 37132805801, 178875434725, 867570709505, 4231667890525, 20736710344601, 102006361694485, 503350999256945
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 15*a(n-1) - 85*a(n-2) + 225*a(n-3) - 274*a(n-4) + 120*a(n-5).
Empirical g.f.: x*(325 - 3874*x + 16055*x^2 - 26930*x^3 + 15000*x^4) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)). - Colin Barker, Apr 01 2018
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EXAMPLE
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Some solutions for 5 X 3:
1 2 1 0 3 0 3 1 2 0 4 0 2 2 2 2 2 2 4 1 1
4 1 4 4 1 4 3 1 4 4 0 4 4 0 4 2 2 2 1 2 4
1 2 1 3 0 3 1 3 0 2 2 2 1 3 1 0 4 0 3 2 0
3 2 3 4 1 4 1 3 2 1 3 1 3 1 3 0 4 0 0 3 3
2 1 2 0 3 0 4 0 3 1 3 1 1 3 1 1 3 1 3 2 0
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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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