a(0)=1, a(1)=4, a(n) = Sum_{k=0..n-1} 4^k*a(k).
A015489
a(0)=1, a(1)=4, a(n) = Sum_{k=0..n-1} 4^k*a(k).
Terms
- a(0) =1a(1) =4a(2) =17a(3) =289a(4) =18785a(5) =4827745a(6) =4948438625
External references
- oeis: A015489
A015489
a(0)=1, a(1)=4, a(n) = Sum_{k=0..n-1} 4^k*a(k).