A369284 Number of point-determining graphs on n unlabeled nodes with no isolated vertices.

1, 0, 1, 1, 4, 12, 66, 522, 7525, 198389, 9816493, 903092383, 153733197077, 48444061519659, 28363852590188969, 30996574583203962119, 63502062798039684795935, 244852576446682783722245053, 1783161675023082411226026322655, 24603891461799405333437840036319801

Offset: 0

Author

Andrew Howroyd, Jan 18 2024

Keywords

• nonn

Comments

Point-determining graphs are also called mating graphs. See A004110 for references.

The inverse Euler transform of this sequence gives A004108 except with a(1) = 0 and a(2) = 1.

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..50

Crossrefs

Cf. A004108, A004110 (point-determining graphs).

Formula

a(n) = A004110(n) - a(n-1) for n > 0.

G.f.: B(x)/(1 + x) where B(x) is the g.f. of A004110.