1,2

By convention, empty graphs are considered edge-transitive.

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

Eric Weisstein's World of Mathematics, Symmetric Graph

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

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 * A265701 A007439 A238622

Adjacent sequences: A286928 A286929 A286930 * A286932 A286933 A286934

nonn,more

Eric W. Weisstein, May 16 2017

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

approved