a(0) = 1; a(n) = Sum_{k=0..n-1} (k+1) * binomial(k+3,3) * binomial(n-1,k) * a(k) * a(n-1-k).
A385980
a(0) = 1; a(n) = Sum_{k=0..n-1} (k+1) * binomial(k+3,3) * binomial(n-1,k) * a(k) * a(n-1-k).
Terms
- a(0) =1a(1) =1a(2) =9a(3) =295a(4) =24921a(5) =4504516a(6) =1543745107a(7) =919392117722
External references
- oeis: A385980