a(n) = 5*401*(10^n + 1).

A107285

a(n) = 5*401*(10^n + 1).

Terms

    a(0) =4010a(1) =22055a(2) =202505a(3) =2007005a(4) =20052005a(5) =200502005a(6) =2005002005a(7) =20050002005a(8) =200500002005

External references