%N Number of connected regular simple graphs on n vertices with girth at least 9.
%H Andries E. Brouwer, <a href="http://www.win.tue.nl/~aeb/graphs/cages/cages.html">Cages</a>
%H House of Graphs, <a href="http://hog.grinvin.org/Cubic">Cubic graphs</a>
%H Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/C_k-reg_girth_ge_g_index">Index of sequences counting connected k-regular simple graphs with girth at least g</a>
%e The null graph is vacuously regular; there is one 0-regular simple graph with 1 vertex, and one 1-regular simple graph with 2 vertices; each of those three graphs, being acyclic, has infinite girth.
%e The n-cycle is the connected 2-regular graph with girth n.
%e The (3,9)-cages have order 58 and there are 18 of them.
%Y Connected regular graphs of any degree with girth at least g: A005177 (g=3), A186724 (g=4), A186725 (g=5), A186726 (g=6), A186727 (g=7), A186728 (g=8), this sequence (g=9).
%Y Connected k-regular simple graphs with girth at least 9: this sequence (all k), A186719 (triangular array), A185119 (k=2).
%A _Jason Kimberley_, Oct 22 2011