Number of essentially parallel oriented series-parallel networks with n elements and without unit elements in parallel.

A339155

Number of essentially parallel oriented series-parallel networks with n elements and without unit elements in parallel.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =3a(6) =5a(7) =13a(8) =29a(9) =70a(10) =165a(11) =409a(12) =1001a(13) =2505a(14) =6278a(15) =15904a(16) =40447a(17) =103567a(18) =266229a(19) =687668a(20) =1782573a(21) =4637731a(22) =12103112a(23) =31679212a(24) =83135973a(25) =218713492a(26) =576683119a(27) =1523740365a(28) =4033915677a(29) =10698680606

External references