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

A339231

Triangle read by rows: T(n,k) is the number of oriented 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) =3a(5) =1a(6) =1a(7) =6a(8) =7a(9) =1a(10) =1a(11) =10a(12) =23a(13) =13a(14) =1a(15) =1a(16) =15a(17) =59a(18) =69a(19) =22a(20) =1a(21) =1a(22) =21a(23) =124a(24) =249a(25) =172a(26) =34a(27) =1a(28) =1a(29) =28

External references