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Search: id:A079502
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| A079502 |
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Triangle T(n,k) read by rows; related to number of preorders. |
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+0
2
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| 1, 1, 2, 1, 5, 5, 1, 10, 24, 16, 1, 18, 79, 122, 61, 1, 31, 223, 602, 680, 272, 1, 52, 579, 2439, 4682, 4155, 1385, 1, 86, 1432, 8856, 25740, 38072, 27776, 7936
(list; table; graph; listen)
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OFFSET
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0,3
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REFERENCES
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G. Kreweras, Les preordres totaux compatibles avec un ordre partiel. Math. Sci. Humaines No. 53 (1976), 5-30. (The numbers u_r^n on page 20.)
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FORMULA
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This is somehow related to the triangle in A050447; it would be nice to have an explicit recurrence!
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EXAMPLE
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1; 1,2; 1,5,5; 1,10,24,16; ...
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CROSSREFS
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Diagonals give A000111, A006326, A006327, A006328.
Adjacent sequences: A079499 A079500 A079501 this_sequence A079503 A079504 A079505
Sequence in context: A021468 A033282 A126350 this_sequence A126124 A060920 A107842
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KEYWORD
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nonn,tabl,easy,more
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AUTHOR
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njas, Jan 21 2003
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