a(n) = 4*(10^n-9).

A177114

a(n) = 4*(10^n-9).

Terms

    a(0) =4a(1) =364a(2) =3964a(3) =39964a(4) =399964a(5) =3999964a(6) =39999964a(7) =399999964a(8) =3999999964a(9) =39999999964a(10) =399999999964

External references