A 3-way generalization of series-parallel networks with n labeled edges.

A058561

A 3-way generalization of series-parallel networks with n labeled edges.

Terms

    a(0) =0a(1) =1a(2) =3a(3) =12a(4) =78a(5) =708a(6) =8256a(7) =117624a(8) =1980096a(9) =38456736a(10) =846413472a(11) =20819693568a(12) =565998548352

External references