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A186746
Number of connected regular simple graphs on n vertices with girth exactly 6.
1
0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 5, 0, 32, 0, 385, 0, 7573, 0, 181225, 0, 4624481, 0, 122090002, 0, 3328899605, 0, 93988911027, 25, 2754128020324, 13504
OFFSET
0,19
FORMULA
a(n) = A186726(n) - A186727(n).
CROSSREFS
Sequence in context: A279548 A279701 A279604 * A208928 A348209 A368768
KEYWORD
nonn,more,hard
AUTHOR
Jason Kimberley, Apr 03 2012
EXTENSIONS
a(36)-a(37) from Jinyuan Wang, Mar 02 2020
STATUS
approved