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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 (list; graph; refs; listen; history; text; internal format)
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).

LINKS

Jason Kimberley, Table of i, a(i)=E(n,g) for i = 2..60 (n = 2..16)

Jason Kimberley, Index of sequences counting not necessarily connected k-regular simple graphs with girth at least 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

Cf. A005638, A185334, A185304.

Sequence in context: A085592 A174421 A089849 * A217955 A325703 A321898

Adjacent sequences:  A185327 A185328 A185329 * A185331 A185332 A185333

KEYWORD

nonn,hard,tabf

AUTHOR

Jason Kimberley, Oct 18 2012

STATUS

approved

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Last modified July 23 13:58 EDT 2019. Contains 325254 sequences. (Running on oeis4.)