A360031 a(n) is the number of unlabeled 2-connected graphs with n edges containing at least one pair of nodes with resistance distance 1 when all edges are replaced by unit resistors.

0, 1, 1, 1, 2, 5, 14, 35, 111, 341, 1130, 3969, 15002, 58429, 239045, 1012241

Offset

3,5

Links

Table of n, a(n) for n=3..18.

Hugo Pfoertner, Illustration of terms a(3)-a(7), 2023.

Crossrefs

Cf. A010355, A339070, A342558, A360030.

Sequence in context: A299164 A131408 A137917 * A244099 A201371 A244061

Adjacent sequences: A360028 A360029 A360030 * A360032 A360033 A360034

Keyword

nonn,more

Author

Hugo Pfoertner, Mar 11 2023

Status

approved