A014376 Number of trivalent connected simple graphs with 2n nodes and girth at least 8.

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 3, 13, 155, 4337, 266362, 20807688

Offset

0,19

References

CRC Handbook of Combinatorial Designs, 1996, p. 647.

M. Meringer, Fast Generation of Regular Graphs and Construction of Cages</a>, Journal of Graph Theory, 30 (1999), 137-146 doi 10.1002/(SICI)1097-0118(199902)30:2<137::AID-JGT7>3.0.CO;2-G [From Jason Kimberley, Jan 29 2011]

Links

Table of n, a(n) for n=0..23.

Jason Kimberley, Connected regular graphs with girth at least 8

Jason Kimberley, Index of sequences counting connected k-regular simple graphs with girth at least g

M. Meringer, Tables of Regular Graphs

Crossrefs

Contribution from Jason Kimberley, May 18 2010 and Jan 29 2011: (Start)

Connected k-regular simple graphs with girth at least 8: A186728 (any k), A186718 (triangle); specific k: A185118 (k=2), this sequence (k=3).

Trivalent simple graphs with girth at least g: A185131 (triangle); chosen g: A002851 (g=3), A014371 (g=4), A014372 (g=5), A014374 (g=6), A014375 (g=7), this sequence (g=8).

Trivalent simple graphs with girth exactly g: A198303 (triangle); chosen g: A006923 (g=3), A006924 (g=4), A006925 (g=5), A006926 (g=6), A006927 (g=7). (End)

Sequence in context: A339025 A317074 A230036 * A224990 A065622 A246418

Adjacent sequences: A014373 A014374 A014375 * A014377 A014378 A014379

Keyword

nonn,more,hard

Author

N. J. A. Sloane.

Extensions

Terms a(21), a(22), and a(23) found by running Meringer's GENREG for 0.15, 5.0, and 176.2 processor days, respectively, at U. Ncle. by Jason Kimberley, May 18 2010

Status

approved