Number of binary trees (i.e., rooted trees where each vertex has either 0, 1, or 2 children; and, when only one child is present, it is either a right child or a left child) with n edges and no adjacent vertices of outdegree 2.

A126220

Number of binary trees (i.e., rooted trees where each vertex has either 0, 1, or 2 children; and, when only one child is present, it is either a right child or a left child) with n edges and no adjacent vertices of outdegree 2.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =14a(4) =40a(5) =116a(6) =344a(7) =1040a(8) =3188a(9) =9880a(10) =30912a(11) =97520a(12) =309856a(13) =990656a(14) =3184672a(15) =10287808a(16) =33379072a(17) =108724864a(18) =355405568a(19) =1165521408a(20) =3833497408a(21) =12642775424a(22) =41799227392a(23) =138512751360a(24) =459973953024

External references