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A166812
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Number of n X 7 1..2 arrays containing at least one of each value, all equal values connected, rows considered as a single number in nondecreasing order, and columns considered as a single number in nondecreasing order.
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3
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6, 34, 118, 328, 790, 1714, 3430, 6433, 11438, 19446, 31822, 50386, 77518, 116278, 170542, 245155, 346102, 480698, 657798, 888028, 1184038, 1560778, 2035798, 2629573, 3365854, 4272046, 5379614, 6724518, 8347678, 10295470, 12620254, 15380935, 18643558, 22481938
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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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G.f.: 1/(1 - x)^8 - 2/(1-x).
E.g.f.: (1/7!)*(-5040 + 35280*x + 52920*x^2 + 29400*x^3 + 7350*x^4 + 882*x^5 + 49*x^6 + x^7)*exp(x). (End)
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EXAMPLE
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Some solutions for n=4
...1.1.1.1.2.2.2...1.1.1.1.2.2.2...1.1.1.1.1.1.1...1.1.1.1.1.1.2
...1.1.1.2.2.2.2...1.1.2.2.2.2.2...1.1.1.1.2.2.2...1.1.1.1.1.1.2
...1.2.2.2.2.2.2...1.1.2.2.2.2.2...1.1.2.2.2.2.2...1.1.1.2.2.2.2
...1.2.2.2.2.2.2...1.2.2.2.2.2.2...1.2.2.2.2.2.2...1.2.2.2.2.2.2
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...1.1.1.1.1.1.2...1.1.1.1.1.1.2...1.1.1.1.1.2.2...1.1.1.1.1.2.2
...1.1.1.2.2.2.2...1.1.1.1.1.2.2...1.1.1.1.1.2.2...1.1.1.2.2.2.2
...1.1.2.2.2.2.2...1.2.2.2.2.2.2...1.1.1.2.2.2.2...1.2.2.2.2.2.2
...2.2.2.2.2.2.2...2.2.2.2.2.2.2...1.1.1.2.2.2.2...2.2.2.2.2.2.2
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MAPLE
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a:= n-> binomial(n+7, 7)-2:
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MATHEMATICA
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Table[Binomial[n+7, 7] -2, {n, 1, 100}] (* G. C. Greubel, May 24 2016 *)
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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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