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A079507
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Triangle T(n,k) read by rows; related to number of preorders.
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0
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1, 1, 4, 4, 1, 15, 63, 96, 48, 1, 44, 468, 1936, 3688, 3264, 1088, 1, 120, 2795, 23990, 98275, 214640, 256720, 158720, 39680
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| Row n has 2n-1 entries.
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REFERENCES
| G. Kreweras, Les preordres totaux compatibles avec un ordre partiel. Math. Sci. Humaines No. 53 (1976), 5-30. (The array on page 22.)
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FORMULA
| How is this array defined?
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EXAMPLE
| 1; 1,4,4; 1,15,63,96,48; ...
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CROSSREFS
| Sequence in context: A145902 A124028 A123966 * A098364 A116866 A126280
Adjacent sequences: A079504 A079505 A079506 * A079508 A079509 A079510
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KEYWORD
| nonn,tabf
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Jan 21 2003
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