A394933 Number of graphs with n vertices that have no induced regular subgraph of order 7 or greater.

1, 2, 4, 11, 34, 156, 1038, 12226, 268920, 11361262, 885194426, 119298229792, 25716285392622

Offset

1,2

Comments

a(n) eventually becomes 0. It is known that a(29)>0 but it is not known whether a(30)=0.

Links

Table of n, a(n) for n=1..13.

Paul W. Dyson and Brendan D. McKay, Ramsey numbers for regular induced subgraphs, arXiv:2604.08215 [math.CO] (2026).

Paul Dyson and Brendan McKay, Ramsey Graphs (section Regular induced subgraphs)

S. Fajtlowicz, T. McColgan, T. Read, and W. Staton, Ramsey numbers for induced regular subgraphs, Ars Combinatoria, 39 (1995) 149-154.

Crossrefs

Cf. A394400 (order 4 or greater), A390919 (order 5 or greater), A392636 (order 6 or greater), A394930 (order 7 only).

Sequence in context: A156809 A215620 A076317 * A394930 A076318 A046750

Adjacent sequences: A394930 A394931 A394932 * A394934 A394935 A394936

Keyword

nonn,hard,more

Author

Brendan McKay, Apr 07 2026

Status

approved