Number of unlabeled digraphs with n arcs and a global source and sink.

A350796

Number of unlabeled digraphs with n arcs and a global source and sink.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =7a(5) =25a(6) =108a(7) =513a(8) =2690a(9) =15230a(10) =92361a(11) =594669a(12) =4040283a(13) =28817783a(14) =214898429a(15) =1669663193a(16) =13476692136a(17) =112722792293a(18) =974931812942

External references