a(n) = Sum_{k=1..n} sigma_{n-1}(k).

A356130

a(n) = Sum_{k=1..n} sigma_{n-1}(k).

Terms

    a(0) =1a(1) =4a(2) =16a(3) =111a(4) =999a(5) =12513a(6) =185683a(7) =3316418a(8) =67810767a(9) =1576561677a(10) =40862702931

External references