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Search: id:A091073
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| A091073 |
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Number of transitive relations on n unlabeled points. |
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+0
3
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| 1, 2, 8, 39, 242, 1895, 19051, 246895, 4145108, 90325655, 2555630036, 93810648902, 4461086120602, 274339212258846, 21775814889230580, 2226876304576948549
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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[ a(13)-a(15) are from Brinkmann's and McKay's paper ] - Vladeta Jovovic (vladeta(AT)Eunet.yu), Jan 07 2006
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REFERENCES
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Gunnar Brinkmann and Brendan D. McKay, Counting Unlabeled Topologies and Transitive Relations, Journal of Integer Sequences, Vol. 8 (2005), Article 05.2.1.
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LINKS
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Gunnar Brinkmann and Brendan D. McKay, Counting unlabeled topologies and transitive relations.
G. Pfeiffer, Counting Transitive Relations, preprint, 2004.
G. Pfeiffer, Counting Transitive Relations, Journal of Integer Sequences, Vol. 7 (2004), Article 04.3.2.
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CROSSREFS
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Cf. A079265 (antisymmetric transitive relations), A001930 (reflexive transitive relations), A000112 (partial orders), A006905 (labeled transitive relations).
Sequence in context: A059275 A020047 A068107 this_sequence A087971 A127919 A074092
Adjacent sequences: A091070 A091071 A091072 this_sequence A091074 A091075 A091076
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KEYWORD
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hard,nonn,nice
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AUTHOR
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Goetz Pfeiffer (goetz.pfeiffer(AT)nuigalway.ie), Jan 21 2004
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EXTENSIONS
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More terms from Vladeta Jovovic (vladeta(AT)Eunet.yu), Jan 07 2006
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