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 A184974 Number of connected 7-regular simple graphs on 2n vertices with girth exactly 4. 7
 0, 0, 0, 0, 0, 0, 0, 1, 1, 8, 741, 2887493 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,10 LINKS FORMULA a(n) = A186714(n,5) - A186715(n,5). EXAMPLE a(0)=0 because even though the null graph (on zero vertices) is vacuously 7-regular 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 k-regular simple graphs with girth exactly 4: A006924 (k=3), A184944 (k=4), A184954 (k=5), A184964 (k=6), this sequence (k=7). Connected 7-regular simple graphs with girth at least g: A014377 (g=3), A181153 (g=4). Connected 7-regular 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

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Last modified January 28 12:07 EST 2022. Contains 350656 sequences. (Running on oeis4.)