

A058786


Number of nhedra with 2n5 vertices or 3n7 edges (the vertices of these are all of degree 3, except one which is of degree 4). Alternatively, the number of polyhedra with n vertices whose faces are all triangular, except one which is tetragonal.


3



1, 2, 8, 38, 219, 1404, 9714, 70454, 527235, 4037671, 31477887, 249026400, 1994599707, 16147744792
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OFFSET

5,2


LINKS

Table of n, a(n) for n=5..18.
G. P. Michon, Counting Polyhedra


EXAMPLE

a(5)=1 because the square pyramid is the only pentahedron with 5=2*55 vertices (or 8=3*57 edges). Alternatively, a(5)=1 because the square pyramid is the only polyhedron with 5 vertices whose faces are all triangles with only one tetragonal exception.


CROSSREFS

Cf. A000109, A002856, A000944, A002840, A058787, A058788, A049337.
Sequence in context: A020031 A179323 A001340 * A096654 A269509 A191016
Adjacent sequences: A058783 A058784 A058785 * A058787 A058788 A058789


KEYWORD

hard,nonn,nice


AUTHOR

Gerard P. Michon, Nov 29 2000


STATUS

approved



