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A182322
Number of simplicial 4-clusters with n cells. (Formerly M2679)
4
1, 1, 1, 3, 7, 30, 131, 795, 5152, 36800, 272093, 2077909, 16176607, 127996683, 1025727646, 8310377720, 67967600763, 560527576100, 4656993996246, 38949328897318, 327718211568300, 2772480181758683, 23571996461405321, 201327668784954950, 1726755218246463325
OFFSET
1,4
COMMENTS
Some of the terms in the Hering article are in error, including the 6th, 8th and 9th.
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
F. Hering et al., The enumeration of stack polytopes and simplicial clusters, Discrete Math., 40 (1982), 203-217.
FORMULA
a(n) = (A007175(n) + A182299(n))/2.
CROSSREFS
This is the average of A007175 and A182299, both of which have Mathematica programs.
Sequence in context: A188229 A277739 A098644 * A132105 A019021 A110505
KEYWORD
nonn,easy
AUTHOR
Robert A. Russell, Apr 24 2012
STATUS
approved