

A184974


Number of connected 7regular simple graphs on 2n vertices with girth exactly 4.


7



0, 0, 0, 0, 0, 0, 0, 1, 1, 8, 741, 2887493
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OFFSET

0,10


LINKS

Table of n, a(n) for n=0..11.
Jason Kimberley, Index of sequences counting connected kregular simple graphs with girth exactly g


FORMULA

a(n) = A186714(n,5)  A186715(n,5).


EXAMPLE

a(0)=0 because even though the null graph (on zero vertices) is vacuously 7regular and connected, since it is acyclic, it has infinite girth.
The a(7)=1 graph is the complete bipartite graph K_{7,7}.


CROSSREFS

Connected kregular simple graphs with girth exactly 4: A006924 (k=3), A184944 (k=4), A184954 (k=5), A184964 (k=6), this sequence (k=7).
Connected 7regular simple graphs with girth at least g: A014377 (g=3), A181153 (g=4).
Connected 7regular simple graphs with girth exactly g: A184973 (g=3), this sequence (g=4).
Sequence in context: A058921 A240283 A181153 * A060183 A262353 A268148
Adjacent sequences: A184971 A184972 A184973 * A184975 A184976 A184977


KEYWORD

nonn,more,hard


AUTHOR

Jason Kimberley, Feb 28 2011


STATUS

approved



