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Search: id:A084546
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| A084546 |
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Triangle read by rows: T(n,k) = C( C(n,2), k) for n >= 1, 0 <= k <= C(n,2). |
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4
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| 1, 1, 1, 1, 3, 3, 1, 1, 6, 15, 20, 15, 6, 1, 1, 10, 45, 120, 210, 252, 210, 120, 45, 10, 1, 1, 15, 105, 455, 1365, 3003, 5005, 6435, 6435, 5005, 3003, 1365, 455, 105, 15, 1, 1, 21, 210, 1330, 5985, 20349, 54264, 116280, 203490, 293930, 352716, 352716, 293930, 203490, 116280, 54264, 20349, 5985, 1330, 210, 21, 1
(list; graph; listen)
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OFFSET
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1,5
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COMMENT
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T(n,k) gives number of labeled simple graphs with n nodes and k edges.
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REFERENCES
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J. L. Gross and J. Yellen, eds., Handbook of Graph Theory, CRC Press, 2004; p. 517.
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EXAMPLE
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1; 1,1; 1,3,3,1; 1,6,15,20,15,6,1; ...
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CROSSREFS
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Cf. A083029. A subset of the rows of Pascal's triangle A007318.
Adjacent sequences: A084543 A084544 A084545 this_sequence A084547 A084548 A084549
Sequence in context: A080858 A144228 A083029 this_sequence A026515 A075772 A142157
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KEYWORD
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nonn,tabf
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AUTHOR
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njas, Jul 13 2003
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