Number of essentially parallel series-parallel networks with n unlabeled edges, multiple edges not allowed.

A058385

Number of essentially parallel series-parallel networks with n unlabeled edges, multiple edges not allowed.

Terms

    a(0) =0a(1) =1a(2) =0a(3) =1a(4) =2a(5) =4a(6) =9a(7) =20a(8) =47a(9) =112a(10) =274a(11) =678a(12) =1709a(13) =4346a(14) =11176a(15) =28966a(16) =75656a(17) =198814a(18) =525496a(19) =1395758a(20) =3723986a(21) =9975314a(22) =26817655a(23) =72332320a(24) =195679137a(25) =530814386a(26) =1443556739a(27) =3934880554a(28) =10748839215a(29) =29420919456

External references