Number of elements in the free semigroup on 2 generators x, y which can be constructed from x and y using at most n multiplications.

A098964

Number of elements in the free semigroup on 2 generators x, y which can be constructed from x and y using at most n multiplications.

Terms

    a(0) =2a(1) =6a(2) =18a(3) =62a(4) =266a(5) =1494a(6) =10862

External references