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Search: id:A166756
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| A166756 |
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Number of nX2 1..3 arrays containing at least one of each value, and all equal values connected. |
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+0
1
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| 0, 24, 174, 642, 1716, 3780, 7314, 12894, 21192, 32976, 49110, 70554, 98364, 133692, 177786, 231990, 297744, 376584, 470142, 580146, 708420, 856884, 1027554, 1222542, 1444056, 1694400, 1975974, 2291274, 2642892, 3033516, 3465930, 3943014, 4467744
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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R. H. Hardin, Table of n, a(n) for n=1..82
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FORMULA
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Empirical: a(n)=4*n^4-8*n^3+11*n^2-13*n+6
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EXAMPLE
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Some solutions for n=4
...1.1...2.3...1.1...3.2...3.3...2.2...2.2...3.1...2.3...2.3...2.1...3.3...1.1
...1.3...2.1...3.1...2.2...3.1...1.2...2.1...2.1...2.2...2.3...2.1...3.2...2.1
...1.2...2.2...2.1...1.1...3.1...1.1...2.3...1.1...2.1...2.3...1.1...3.1...3.3
...2.2...2.2...1.1...1.1...2.1...3.3...3.3...1.1...1.1...1.1...3.3...1.1...3.3
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...3.3...1.3...1.2...1.2...3.3...3.1...3.2...3.3...2.1...3.2...1.1...2.2...1.1
...3.1...1.1...1.2...1.3...3.3...3.3...3.3...3.2...1.1...3.3...1.3...2.1...2.2
...1.1...1.2...1.1...3.3...1.1...3.3...3.3...2.2...3.1...3.3...1.1...2.2...2.2
...2.1...2.2...3.1...3.3...2.1...2.2...1.1...2.1...1.1...1.3...2.2...3.2...2.3
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CROSSREFS
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Sequence in context: A136380 A019583 A087887 this_sequence A165187 A052761 A073993
Adjacent sequences: A166753 A166754 A166755 this_sequence A166757 A166758 A166759
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KEYWORD
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nonn
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AUTHOR
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Ron Hardin (rhhardin(AT)att.net) Oct 21 2009
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