OFFSET
0,4
COMMENTS
A path is Hamiltonian if it passes through every vertex exactly once.
LINKS
Wikipedia, Hamiltonian path
Gus Wiseman, Enumeration of paths and cycles and e-coefficients of incomparability graphs, arXiv:0709.0430 [math.CO], 2007.
MATHEMATICA
Table[Length[Select[Subsets[Subsets[Range[n], {2}]], FindHamiltonianPath[Graph[Range[n], #]]=={}&]], {n, 0, 4}] (* Mathematica 10.2+ *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Jun 14 2019
EXTENSIONS
a(7)-a(11) added from formula by Falk Hüffner, Jun 21 2019
STATUS
approved