a(1)=1, a(n) = n*20^(n-1) + a(n-1).

A014937

a(1)=1, a(n) = n*20^(n-1) + a(n-1).

Terms

    a(0) =1a(1) =41a(2) =1241a(3) =33241a(4) =833241a(5) =20033241a(6) =468033241a(7) =10708033241a(8) =241108033241

External references