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A035351
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Number of labeled rooted polygonal cacti with bridges (mixed Husimi trees) with n nodes.
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1
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1, 2, 12, 124, 1810, 34056, 783874, 21331136, 669902076, 23845794400, 948733833256, 41721533664768, 2009539243299328, 105209055401980544, 5948937678563109000, 361296961279074942976, 23456120142707873968336
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Index entries for sequences related to cacti
Index entries for sequences related to rooted trees
Index entries for sequences related to trees
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FORMULA
| E.g.f. satisfies A(x)=x*exp((2*A(x)-A(x)^2)/(2-2*A(x))).
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MAPLE
| A:= proc(n) option remember; if n<=0 then x else x* exp ((2*A(n-1) -A(n-1)^2)/ (2-2*A(n-1))) fi end: a:= n-> coeff (series (A(n-1), x=0, n+1), x, n)*n!: seq (a(n), n=1..18); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Aug 20 2008]
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CROSSREFS
| Cf. A000083, A000237, A000314, A035082, A035349-A035357.
Sequence in context: A013469 A039933 A173219 * A201470 A003712 A143136
Adjacent sequences: A035348 A035349 A035350 * A035352 A035353 A035354
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KEYWORD
| nonn,eigen
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AUTHOR
| Christian G. Bower (bowerc(AT)usa.net), Nov 15 1998.
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EXTENSIONS
| More terms from Alois P. Heinz (heinz(AT)hs-heilbronn.de), Aug 20 2008
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