a(n) = (5*11^n - 1)/2.
A199021
a(n) = (5*11^n - 1)/2.
Terms
- a(0) =2a(1) =27a(2) =302a(3) =3327a(4) =36602a(5) =402627a(6) =4428902a(7) =48717927a(8) =535897202a(9) =5894869227a(10) =64843561502a(11) =713279176527
External references
- oeis: A199021
A199021
a(n) = (5*11^n - 1)/2.