Bisection of A001189.

A066221

Bisection of A001189.

Terms

    a(0) =0a(1) =3a(2) =25a(3) =231a(4) =2619a(5) =35695a(6) =568503a(7) =10349535a(8) =211799311a(9) =4809701439a(10) =119952692895

External references