a(n) = 4*(10^n-7).

A177112

a(n) = 4*(10^n-7).

Terms

    a(0) =12a(1) =372a(2) =3972a(3) =39972a(4) =399972a(5) =3999972a(6) =39999972a(7) =399999972a(8) =3999999972a(9) =39999999972a(10) =399999999972

External references