a(1) = 1, a(n) = Sum_{k=1..n-1} ((10^k - 1)/9)*a(k).
A015512
a(1) = 1, a(n) = Sum_{k=1..n-1} ((10^k - 1)/9)*a(k).
Terms
- a(0) =1a(1) =1a(2) =12a(3) =1344a(4) =1494528a(5) =16607195136
External references
- oeis: A015512
A015512
a(1) = 1, a(n) = Sum_{k=1..n-1} ((10^k - 1)/9)*a(k).