Number of binary trees with n internal nodes that contain the subtree [Z, [Z, U, U], [Z, U, U]].

A331951

Number of binary trees with n internal nodes that contain the subtree [Z, [Z, U, U], [Z, U, U]].

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =2a(5) =6a(6) =20a(7) =69a(8) =246a(9) =894a(10) =3292a(11) =12242a(12) =45868a(13) =172884a(14) =654792a(15) =2489981a(16) =9500774a(17) =36356214a(18) =139471404a(19) =536217814a(20) =2065543012a(21) =7970227084a(22) =30801517624a(23) =119198827218a(24) =461863265660

External references