Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 2.

A244531

Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 2.

Terms

    a(0) =1a(1) =0a(2) =2a(3) =5a(4) =11a(5) =28a(6) =78a(7) =201a(8) =532a(9) =1441a(10) =3895a(11) =10569a(12) =28926a(13) =79493a(14) =219226a(15) =607189a(16) =1687880a(17) =4706737a(18) =13165215a(19) =36929595a(20) =103860429a(21) =292808814a(22) =827392709a(23) =2342964435a(24) =6647953886a(25) =18898472568a(26) =53818654942a(27) =153518738980a(28) =438602656951

External references