OFFSET
0,1
COMMENTS
"Up to direction" means that cycles differing only in starting vertex or direction of traversal are treated as one cycle. a(n) always exists since the wheel graph on n spokes has n cycles.
LINKS
Jeremy Tan, Table of n, a(n) for n = 0..4890
Andreas Björklund, Determinant Sums for Undirected Hamiltonicity, arXiv preprint arXiv:1008.0541 [cs.DS], 2010.
Erich Friedman, Math Magic (September 2012)
EXAMPLE
a(3) = 4 since K_4 has 3 Hamiltonian cycles up to direction.
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Jeremy Tan, Nov 08 2014
STATUS
approved