A333162 Number of regular graphs on n unlabeled nodes with half-edges.

1, 2, 4, 6, 11, 16, 38, 78, 304, 1672, 19630, 450154, 20198620, 1673850034, 252574719718, 69216356716672, 34559361669877526, 31561018687380681802, 52958472442027295300520, 163901411216705405946164728, 939523329928455089556983977702

Offset

0,2

Comments

A half-edge is like a loop except it only adds 1 to the degree of its vertex.

Links

Table of n, a(n) for n=0..20.

Crossrefs

Row sums of A333161.

Cf. A322698, A333159.

Sequence in context: A056342 A094719 A294811 * A336307 A336134 A255214

Adjacent sequences: A333159 A333160 A333161 * A333163 A333164 A333165

Keyword

nonn

Author

Andrew Howroyd, Mar 11 2020

Status

approved