A193125 Number of molecular topological index-nonunique connected simple graphs on n nodes.

0, 0, 0, 2, 12, 87, 815, 11086, 261042

Offset

1,4

Links

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

Eric Weisstein's World of Mathematics, Molecular Topological Index

Example

The paw graph and square graph C_4 both have MTI = 48, while all other 4-node connected simple graphs have unique MTI values, so a(4) = 2.

Crossrefs

Sequence in context: A305209 A290568 A181345 * A305868 A356830 A319324

Adjacent sequences: A193122 A193123 A193124 * A193126 A193127 A193128

Keyword

nonn,hard,more

Author

Eric W. Weisstein, Jul 16 2011

Status

approved