a(n) = Sum_{k=0..n} binomial(3*n,k) * binomial(3*n-k-1,n-k).
A370097
a(n) = Sum_{k=0..n} binomial(3*n,k) * binomial(3*n-k-1,n-k).
Terms
- a(0) =1a(1) =5a(2) =49a(3) =545a(4) =6401a(5) =77505a(6) =956929a(7) =11976193a(8) =151388161a(9) =1928363009a(10) =24712450049a(11) =318255628289
External references
- oeis: A370097