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Search: id:A069724
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| A069724 |
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Number of nonisomorphic unrooted unicursal planar maps with n edges (unicursal means that exactly two vertices are of odd valency; there is an Eulerian path). |
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7
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| 1, 2, 9, 38, 214, 1253, 7925, 51620, 346307, 2365886, 16421359, 115384738, 819276830, 5868540399, 42357643916, 307753571520, 2249048959624, 16520782751969, 121915128678131, 903391034923548, 6719098772562182
(list; graph; listen)
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OFFSET
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1,2
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REFERENCES
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V. A. Liskovets and T. R. S. Walsh, Enumeration of Eulerian and unicursal planar maps, Discr. Math., 282 (2004), 209-221.
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FORMULA
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There is an easy formula.
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CROSSREFS
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Cf. A069720, A069727, A005470.
Sequence in context: A001077 A105484 A057647 this_sequence A132961 A070017 A054129
Adjacent sequences: A069721 A069722 A069723 this_sequence A069725 A069726 A069727
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KEYWORD
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easy,nice,nonn
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AUTHOR
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Valery A. Liskovets (liskov(AT)im.bas-net.by), Apr 07 2002
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