a(n) = 4*(10^n-3).

A177108

a(n) = 4*(10^n-3).

Terms

    a(0) =28a(1) =388a(2) =3988a(3) =39988a(4) =399988a(5) =3999988a(6) =39999988a(7) =399999988a(8) =3999999988a(9) =39999999988a(10) =399999999988

External references