A218553 Order of (5,n) cage, i.e., minimal order of 5-regular graph of girth n.

6, 10, 30, 42

Offset: 3

Author

Arkadiusz Wesolowski, Nov 02 2012

Keywords

• hard
• more
• nonn

Comments

a(7) <= 152, a(8) = 170, a(12) = 2730. - From Royle's page via Jason Kimberley, Dec 21 2012

Links

• Andries E. Brouwer, Cages
• Geoff Exoo, Regular graphs of given degree and girth
• G. Exoo and R. Jajcay, Dynamic cage survey, Electr. J. Combin. (2008, 2011).
• Gordon Royle, Cages of higher valency
• Eric Weisstein's World of Mathematics, Cage Graph (claims too much)

Crossrefs

Orders of cages: A054760 (n,k), A000066 (3,n), A037233 (4,n), this sequence (5,n), A218554 (6,n), A218555 (7,n), A191595 (n,5).

Formula

a(n) >= A061547(n+1).

Extensions

a(7) deleted by Jason Kimberley, Dec 21 2012