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A166781
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Number of nX3 1..2 arrays containing at least one of each value, all equal values connected, and rows considered as a single number in nondecreasing order.
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0
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4, 17, 44, 91, 164, 269, 412, 599, 836, 1129, 1484, 1907, 2404, 2981, 3644, 4399, 5252, 6209, 7276, 8459, 9764, 11197, 12764, 14471, 16324, 18329, 20492, 22819, 25316, 27989, 30844, 33887, 37124, 40561, 44204, 48059, 52132, 56429, 60956, 65719, 70724
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = n^3 + n^2 + 3*n - 1.
Empirical G.f.: x*(x^3 + x + 4)/(1-x)^4.
Empirical E.g.f.: (-1 + 5*x + 4*x^2 + x^3)*exp(x) + 1. (End)
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EXAMPLE
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Some solutions for n=4
...1.1.2...1.1.1...1.1.1...1.1.1...2.2.1...1.1.1...1.1.1...1.1.2...1.1.1
...1.1.2...2.1.2...1.1.2...1.1.1...2.2.1...1.1.1...1.2.1...2.1.2...2.2.1
...1.2.2...2.2.2...2.2.2...1.1.2...2.2.1...1.2.1...1.2.2...2.1.2...2.2.1
...2.2.2...2.2.2...2.2.2...1.1.2...2.2.2...1.2.1...2.2.2...2.2.2...2.2.2
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...1.1.1...1.2.2...1.1.1...1.2.2...2.1.1...1.1.1...2.2.1...2.1.2...1.1.1
...1.1.1...2.2.2...1.1.2...1.2.2...2.2.1...1.1.1...2.2.1...2.1.2...1.1.1
...1.1.1...2.2.2...1.1.2...1.2.2...2.2.1...1.1.2...2.2.2...2.1.2...1.1.1
...2.2.1...2.2.2...2.2.2...1.2.2...2.2.2...1.2.2...2.2.2...2.2.2...2.1.1
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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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