Number of n-leaf binary trees that do not contain (()(()(()((()())())))) as a subtree.

A159768

Number of n-leaf binary trees that do not contain (()(()(()((()())())))) as a subtree.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =41a(6) =124a(7) =385a(8) =1221a(9) =3939a(10) =12886a(11) =42648a(12) =142544a(13) =480459a(14) =1631287a(15) =5574073a(16) =19153815a(17) =66146259a(18) =229452587a(19) =799140681a(20) =2793373937a(21) =9796395680a(22) =34459558856a(23) =121548541383a(24) =429823475811

External references