OFFSET
5,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 5..500
CombOS - Combinatorial Object Server, generate planar graphs
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.
PROG
(PARI) A342053ColSeq(25, 4) \\ See links in A342053. - Andrew Howroyd, Feb 28 2021
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
Gerard P. Michon, Nov 29 2000
EXTENSIONS
Terms a(19) and beyond from Andrew Howroyd, Feb 27 2021
STATUS
approved