Number of hybrid 4-ary trees with n internal nodes.

A239107

Number of hybrid 4-ary trees with n internal nodes.

Terms

    a(0) =1a(1) =2a(2) =15a(3) =155a(4) =1854a(5) =24124a(6) =331575a(7) =4736345a(8) =69616637a(9) =1046054129a(10) =15995716263a(11) =248111418112

External references