a(n) = 5*(10^n-7).

A177080

a(n) = 5*(10^n-7).

Terms

    a(0) =15a(1) =465a(2) =4965a(3) =49965a(4) =499965a(5) =4999965a(6) =49999965a(7) =499999965a(8) =4999999965a(9) =49999999965a(10) =499999999965

External references