A193217 Number of non-Wiener index-unique simple connected graphs on n nodes.

0, 0, 0, 2, 16, 108, 847, 11110, 261072

Offset

1,4

Comments

The paw graph and square graph C_4 on 4 have common Wiener index 8, while all other connected simple graphs on 4 nodes have unique Wiener indices, so a(4) = 2.

Links

Table of n, a(n) for n=1..9.

Eric Weisstein's World of Mathematics, Wiener Index

Crossrefs

Sequence in context: A012024 A349008 A366635 * A329550 A208137 A207435

Adjacent sequences: A193214 A193215 A193216 * A193218 A193219 A193220

Keyword

nonn,hard,more

Author

Eric W. Weisstein, Jul 18 2011

Status

approved