a(n) is the number of ways n^n can be written as s^t*u^v, where s, t, u, v are integers > 1 and s^t <= u^v.

A390604

a(n) is the number of ways n^n can be written as s^t*u^v, where s, t, u, v are integers > 1 and s^t <= u^v.