Triangle read by rows: T(n,k) is the number of unoriented series-parallel networks whose multigraph has n edges and k interior vertices, 0 <= k < n.

A339285

Triangle read by rows: T(n,k) is the number of unoriented series-parallel networks whose multigraph has n edges and k interior vertices, 0 <= k < n.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =1a(7) =4a(8) =5a(9) =1a(10) =1a(11) =6a(12) =14a(13) =8a(14) =1a(15) =1a(16) =9a(17) =34a(18) =39a(19) =14a(20) =1a(21) =1a(22) =12a(23) =68a(24) =132a(25) =94a(26) =20a(27) =1a(28) =1a(29) =16

External references