Total number of interior nodes in all series-parallel networks with n labeled edges, multiple edges not allowed.

A058406

Total number of interior nodes in all series-parallel networks with n labeled edges, multiple edges not allowed.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =2a(4) =27a(5) =199a(6) =2645a(7) =34236a(8) =560742a(9) =9958754a(10) =201928954a(11) =4480386932a(12) =109410252512

External references