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A058786 Number of n-hedra with 2n-5 vertices or 3n-7 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 (list; graph; refs; listen; history; text; internal format)
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*5-5 vertices (or 8=3*5-7 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 A191016 A060389

Adjacent sequences:  A058783 A058784 A058785 * A058787 A058788 A058789

KEYWORD

hard,nonn,nice

AUTHOR

Gerard P. Michon, Nov 29 2000

STATUS

approved

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Last modified April 17 08:56 EDT 2014. Contains 240634 sequences.