

A186717


Irregular triangle C(n,k): the number of connected kregular graphs on n vertices having girth at least seven.


11



1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 3, 0, 0, 1, 0, 0, 0, 1, 21, 0, 0, 1, 0, 0, 0, 1, 546, 0, 0, 1, 0, 0, 0, 1, 30368
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OFFSET

1,74


LINKS

Jason Kimberley, Table of i, a(i) for i = 1..126 (n = 1..39)
Jason Kimberley, Connected regular graphs with girth at least 7
Jason Kimberley, Index of sequences counting connected kregular simple graphs with girth at least g


EXAMPLE

1;
0, 1;
0, 0;
0, 0;
0, 0;
0, 0;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1;
0, 0, 1, 1;
0, 0, 1, 0;
0, 0, 1, 3;
0, 0, 1, 0;
0, 0, 1, 21;
0, 0, 1, 0;
0, 0, 1, 546;
0, 0, 1, 0;
0, 0, 1, 30368;
0, 0, 1, 0;
0, 0, 1, 1782840;
0, 0, 1, 0;
0, 0, 1, 95079083;
0, 0, 1, 0;
0, 0, 1, 4686063120;
0, 0, 1, 0;


CROSSREFS

Triangular arrays C(n,k) counting connected simple kregular graphs on n vertices with girth at least g: A068934 (g=3), A186714 (g=4), A186715 (g=5), A186716 (g=6), this sequence (g=7), A186718 (g=8), A186719 (g=9).
Connected kregular simple graphs with girth at least 7: A186727 (any k), this sequence (triangle); specific k: A185117 (k=2), A014375 (k=3).
Triangular arrays C(n,k) counting connected simple kregular graphs on n vertices with girth exactly g: A186733 (g=3), A186734 (g=4).
Sequence in context: A192732 A092573 A307801 * A233286 A305802 A186038
Adjacent sequences: A186714 A186715 A186716 * A186718 A186719 A186720


KEYWORD

nonn,hard,tabf


AUTHOR

Jason Kimberley, Nov 28 2011


STATUS

approved



