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Search: id:A000083
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| A000083 |
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Number of mixed Husimi trees with n nodes; or polygonal cacti with bridges.
(Formerly M1191 N0461)
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+0
12
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| 1, 1, 1, 2, 4, 9, 23, 63, 188, 596, 1979, 6804, 24118, 87379, 322652, 1209808, 4596158, 17657037, 68497898, 268006183, 1056597059, 4193905901, 16748682185, 67258011248, 271452424286, 1100632738565, 4481533246014
(list; graph; listen)
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OFFSET
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0,4
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
G. W. Ford and G. E. Uhlenbeck, Combinatorial problems in the theory of graphs III, Proc. Nat. Acad. Sci. USA, 42 (1956), 529-535.
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LINKS
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Christian G. Bower, Table of n, a(n) for n=0..500
Index entries for sequences related to cacti
Index entries for sequences related to trees
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FORMULA
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G.f.: A(x)=B(x)+C(x)-B(x)*D(x), B, C, D resp gfs of A000237, A035349, A035350.
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CROSSREFS
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Cf. A000237, A000314, A035082, A035349-A035357.
Sequence in context: A058585 A001573 A135307 this_sequence A092668 A164039 A014137
Adjacent sequences: A000080 A000081 A000082 this_sequence A000084 A000085 A000086
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
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More terms and formula from Christian G. Bower (bowerc(AT)usa.net), Nov 15 1998
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