Number of unlabeled loopless multigraphs with n edges rooted at two indistinguishable vertices.

A339066

Number of unlabeled loopless multigraphs with n edges rooted at two indistinguishable vertices.

Terms

    a(0) =1a(1) =3a(2) =12a(3) =44a(4) =171a(5) =664a(6) =2688a(7) =11133a(8) =47682a(9) =210275a(10) =955940a(11) =4473128a(12) =21532160a(13) =106504216a(14) =540824997a(15) =2816636171a(16) =15031261538a(17) =82123830645a(18) =458979942506

External references