Hybrid binary rooted trees with n nodes whose root is labeled by "n".

A011270

Hybrid binary rooted trees with n nodes whose root is labeled by "n".

Terms

    a(0) =1a(1) =1a(2) =4a(3) =18a(4) =90a(5) =481a(6) =2690a(7) =15547a(8) =92124a(9) =556664a(10) =3417062a(11) =21248966a(12) =133576724a(13) =847465593a(14) =5419399722a(15) =34895368578a(16) =226050057378

External references