A394930 Number of graphs with n vertices that have no induced regular subgraph of order 7.

1, 2, 4, 11, 34, 156, 1038, 12246, 269646, 11453460, 907948002, 127924347122, 30302185606487

Offset

1,2

Comments

The sequence eventually becomes zero. It is known that a(70)>0, but it is not known whether a(71)=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. A394573 (subgraphs of order 4), A394539 (order 5), A394462 (order 6), A394933 (order 7 or greater).

Sequence in context: A215620 A076317 A394933 * A076318 A046750 A076319

Adjacent sequences: A394927 A394928 A394929 * A394931 A394932 A394933

Keyword

nonn,hard,more

Author

Brendan McKay, Apr 07 2026

Status

approved