a(n) = Sum_{k=0..floor(n/2)} n^(3*k) * binomial(n-k,k).
A368889
a(n) = Sum_{k=0..floor(n/2)} n^(3*k) * binomial(n-k,k).
Terms
- a(0) =1a(1) =1a(2) =9a(3) =55a(4) =4289a(5) =47376a(6) =10358713a(7) =162592977a(8) =70065589761
External references
- oeis: A368889