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A166826
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Number of nX2 1..4 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 nonincreasing order.
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1
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0, 4, 49, 219, 666, 1636, 3499, 6783, 12212, 20748, 33637, 52459, 79182, 116220, 166495, 233503, 321384, 434996, 579993, 762907, 991234, 1273524, 1619475, 2040031, 2547484, 3155580, 3879629, 4736619, 5745334, 6926476, 8302791, 9899199
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| R. H. Hardin, Table of n, a(n) for n=1..44
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FORMULA
| Empirical: a(n)=(n^6+18*n^5+100*n^4-731*n^2+792*n-180)/180
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EXAMPLE
| All solutions for n=3
...1.1...1.1...1.1...1.1...1.1...1.1...1.1...1.1...1.1...2.1...2.1...2.1...2.1
...2.1...2.1...2.2...3.1...3.2...3.2...3.2...3.3...4.2...2.1...2.1...2.2...2.2
...3.4...4.3...4.3...4.2...3.4...4.2...4.4...4.2...4.3...3.4...4.3...3.4...4.3
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...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1
...2.3...2.3...2.3...2.4...2.4...3.1...3.1...3.1...3.3...3.3...3.3...3.4...3.4
...2.4...4.3...4.4...3.3...3.4...3.4...4.1...4.4...3.4...4.3...4.4...3.4...4.4
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...2.1...2.1...2.1...2.2...2.2...2.2...2.2...2.2...2.2...3.1...3.1...3.1...3.1
...4.1...4.3...4.3...3.1...3.1...3.1...3.2...3.3...4.1...3.1...3.2...3.2...3.2
...4.3...4.3...4.4...3.4...4.1...4.4...4.1...4.1...4.3...4.2...3.4...4.2...4.4
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...3.1...3.1...3.1...3.1...3.2...3.2...3.2...3.2...3.3...4.1
...3.3...4.1...4.2...4.2...3.2...3.3...4.1...4.1...4.1...4.2
...4.2...4.2...4.2...4.4...4.1...4.1...4.1...4.4...4.2...4.3
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CROSSREFS
| Sequence in context: A092866 A041065 A166838 * A078187 A100256 A163944
Adjacent sequences: A166823 A166824 A166825 * A166827 A166828 A166829
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KEYWORD
| nonn
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AUTHOR
| R. H. Hardin (rhhardin(AT)att.net) Oct 21 2009
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