A286931 Number of (not necessarily connected) symmetric (edge- and vertex-transitive) graphs with n nodes.

1, 2, 2, 4, 3, 7, 3, 9, 6, 12, 3, 20, 5, 12, 14

Offset

1,2

Comments

By convention, empty graphs are considered edge-transitive.

Links

Table of n, a(n) for n=1..15.

Eric Weisstein's World of Mathematics, Symmetric Graph

Formula

a(n) = Sum{d|n} A133181(d). - Charlie Neder, Apr 24 2019

Crossrefs

Cf. A133181 (number of connected symmetric graphs on n nodes).

Cf. A087145 (number of disconnected symmetric graphs on n nodes).

Sequence in context: A122585 A057449 A308601 * A336305 A265701 A353747

Adjacent sequences: A286928 A286929 A286930 * A286932 A286933 A286934

Keyword

nonn,more

Author

Eric W. Weisstein, May 16 2017

Extensions

a(11)-a(15) from Charlie Neder, Apr 24 2019

Status

approved