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A185330
Irregular triangle E(n,g) counting not necessarily connected 3-regular simple graphs on 2n vertices with girth at least g.
2
1, 2, 1, 6, 2, 21, 6, 1, 94, 23, 2, 540, 112, 9, 1, 4207, 801, 49, 1, 42110, 7840, 455, 5, 516344, 97723, 5784, 32, 7373924, 1436873, 90940, 385, 118573592, 23791155, 1620491, 7574, 1, 2103205738, 432878091, 31478651, 181227, 3, 40634185402
OFFSET
2,2
COMMENTS
The first column is for girth at least 3. The row length is incremented to g-2 when 2n reaches A000066(g).
EXAMPLE
1;
2, 1;
6, 2;
21, 6, 1;
94, 23, 2;
540, 112, 9, 1;
4207, 801, 49, 1;
42110, 7840, 455, 5;
516344, 97723, 5784, 32;
7373924, 1436873, 90940, 385;
118573592, 23791155, 1620491, 7574, 1;
2103205738, 432878091, 31478651, 181227, 3;
40634185402, 8544173926, 656784488, 4624502, 21;
847871397424, 181519645163, 14621878339, 122090545, 546, 1;
18987149095005, 4127569521160, 345975756388, 3328929960, 30368, 0;
CROSSREFS
KEYWORD
nonn,hard,tabf
AUTHOR
Jason Kimberley, Oct 18 2012
STATUS
approved