a(n) = Sum_{k=0..n} binomial(3*n+1,k) * binomial(3*n-k,n-k).
A383326
a(n) = Sum_{k=0..n} binomial(3*n+1,k) * binomial(3*n-k,n-k).
Terms
- a(0) =1a(1) =7a(2) =71a(3) =799a(4) =9439a(5) =114687a(6) =1419263a(7) =17791487a(8) =225172991a(9) =2870945791a(10) =36819740671a(11) =474470776831
External references
- oeis: A383326