login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A279022
Greatest possible number of diagonals of a polyhedron having n edges.
5
0, 1, 1, 2, 4, 5, 7, 10, 13, 16, 20, 23, 28, 34, 37, 44, 52, 55, 64, 73, 77, 88, 100, 103, 115, 128, 133
OFFSET
8,4
COMMENTS
Note that a polyhedron with 6 edges (a tetrahedron) has no diagonals and a polyhedron having exactly 7 edges does not exist.
If n = 3k where k > 3 than the maximum number of diagonals is achieved by a simple polyhedron with k+2 faces.
According to the Grünbaum-Motzkin Theorem a(3k) = 2*k^2-13*k+30, for all k>11.
Additionally for all k>11 a(3k+1) <= 2*k^2-13*k+36 and a(3k+2) <= 2*k^2-11*k+27.
REFERENCES
1. B. Grünbaum, Convex Polytopes, 2nd edition, Springer, 2003.
LINKS
B. Grünbaum, T. S. Motzkin, The number of hexagons and the simplicity of geodesics of certain polyhedra , Canadian journal of Mathematics, 15 (1963), pp. 744-751.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vladimir Letsko, Dec 03 2016
STATUS
approved