A128042 - OEIS

A128042

Triangle read by columns: number of n-node (unlabeled) connected graphs with girth k, for n >= 3, k >= 3.

1, 3, 1, 15, 2, 1, 93, 11, 1, 1, 794, 41, 5, 1, 1, 10850, 220, 16, 6, 1, 1, 259700, 1243, 66, 17, 5, 1, 1, 11706739, 9368, 266, 69, 15, 6, 1, 1, 1006609723, 89049, 1235, 239, 58, 18, 6, 1, 1, 164058686415, 1135894, 6350, 962, 202, 74, 19, 7, 1, 1

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

OFFSET

3,2

LINKS

Georg Grasegger, Table of n, a(n) for n = 3..122

EXAMPLE

Number of n-node (unlabeled) connected graphs with girth k:

.k..|.n=........3........4........5........6........7........8........9........10

---------------------------------------------------------------------------------

.0..|...........0........0........0........0........0........0........0.........0

.1..|...........0........0........0........0........0........0........0.........0

.2..|...........0........0........0........0........0........0........0.........0

.3..|...........1........3.......15.......93......794....10850...259700..11706739

.4..|...........0........1........2.......11.......41......220.....1243......9368

.5..|...........0........0........1........1........5.......16.......66.......266

.6..|...........0........0........0........1........1........6.......17........69

.7..|...........0........0........0........0........1........1........5........15

.8..|...........0........0........0........0........0........1........1.........6

.9..|...........0........0........0........0........0........0........1.........1

10..|...........0........0........0........0........0........0........0.........1

11..|...........0........0........0........0........0........0........0.........0

PROG

(nauty) geng -c $n | countg --ng

# Martin Fuller, May 03 2015

CROSSREFS

Sequences for k=3..6 are A128240, A128241, A128242, A128243.

Cf. A128041, A006787, A128236, A128237, A128238, A128239.

Cf. A325455 (circumference).

Sequence in context: A176727 A080924 A232179 * A108083 A163239 A134145

Adjacent sequences: A128039 A128040 A128041 * A128043 A128044 A128045

KEYWORD

nonn,tabl

AUTHOR

Keith Briggs, May 05 2007

EXTENSIONS

Corrected and extended by Martin Fuller, May 01 2015

STATUS

approved