a(n) = 5*10^n - 1.
A198971
a(n) = 5*10^n - 1.
Terms
- a(0) =4a(1) =49a(2) =499a(3) =4999a(4) =49999a(5) =499999a(6) =4999999a(7) =49999999a(8) =499999999a(9) =4999999999a(10) =49999999999a(11) =499999999999
External references
- oeis: A198971
A198971
a(n) = 5*10^n - 1.