

A000237


Number of mixed Husimi trees with n nodes; or rooted polygonal cacti with bridges.
(Formerly M2754 N1107)


12



0, 1, 1, 3, 8, 26, 84, 297, 1066, 3976, 15093, 58426, 229189, 910127, 3649165, 14756491, 60103220, 246357081, 1015406251, 4205873378, 17497745509, 73084575666, 306352303774, 1288328048865, 5433980577776, 22982025183983
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OFFSET

0,4


REFERENCES

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Christian G. Bower, Table of n, a(n) for n=0..500
C. G. Bower, Transforms (2)
G. W. Ford and G. E. Uhlenbeck, Combinatorial problems in the theory of graphs III, Proc. Nat. Acad. Sci. USA, 42 (1956), 529535.
N. J. A. Sloane, Transforms
Index entries for sequences related to cacti
Index entries for sequences related to rooted trees
Index entries for sequences related to trees


FORMULA

Shifts left under transform T where Ta = EULER(BIK(a)). [See Transforms links.]  Christian G. Bower, Nov 15 1998


CROSSREFS

Cf. A000083, A000314, A035082, A035349A035357.
Sequence in context: A148803 A148804 A148805 * A148806 A148807 A148808
Adjacent sequences: A000234 A000235 A000236 * A000238 A000239 A000240


KEYWORD

nonn,eigen,nice,easy,changed


AUTHOR

N. J. A. Sloane


EXTENSIONS

More terms from Christian G. Bower, Nov 15 1998


STATUS

approved



