A249906 a(n) is the index of the first occurrence of n in A249905, or -1 if n does not occur.

1, 0, -1, 3, 2, 5, 9, 13, 89, 485, 4891

Offset: 1

Author

Jeremy Tan, Nov 08 2014

Keywords

• sign
• hard
• more

Comments

a(n) is the smallest number of Hamiltonian cycles up to direction which requires at least an n-vertex graph to realize.

Links

• Erich Friedman, Math Magic (September 2012)

Extensions

a(10)-a(11) using data from Johan de Ruiter added by Jeremy Tan, Nov 02 2018