Number of subgroups of index n in fundamental group of a certain fiber space.

A027840

Number of subgroups of index n in fundamental group of a certain fiber space.

Terms

    a(0) =1a(1) =15a(2) =220a(3) =5275a(4) =151086a(5) =6605004a(6) =362069912a(7) =26370058035

External references