a(1) = 1, a(n) = Sum_{k=1..n-1} ((9^k - 1)/8)*a(k).
A015511
a(1) = 1, a(n) = Sum_{k=1..n-1} ((9^k - 1)/8)*a(k).
Terms
- a(0) =1a(1) =1a(2) =11a(3) =1012a(4) =830852a(5) =6133349464
External references
- oeis: A015511
A015511
a(1) = 1, a(n) = Sum_{k=1..n-1} ((9^k - 1)/8)*a(k).