Number of (unordered) plane trees with n leaves, such that for every node the number of "children of children" has no common divisor > 1.

A354076

Number of (unordered) plane trees with n leaves, such that for every node the number of "children of children" has no common divisor > 1.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =23a(6) =60a(7) =153a(8) =405a(9) =1076a(10) =2909a(11) =7907a(12) =21693a(13) =59834a(14) =166004a(15) =462612a(16) =1294612a(17) =3635809a(18) =10244017

External references