Number of inequivalent colorings of oriented series-parallel networks with n colored elements.

A339233

Number of inequivalent colorings of oriented series-parallel networks with n colored elements.

Terms

    a(0) =1a(1) =4a(2) =21a(3) =165a(4) =1609a(5) =19236a(6) =266251a(7) =4175367a(8) =72705802a(9) =1387084926a(10) =28689560868a(11) =638068960017

External references