a(n) = [x^n] Product_{k=1..3*n} 1/(1 - k*x).

A383881

a(n) = [x^n] Product_{k=1..3*n} 1/(1 - k*x).

Terms

    a(0) =1a(1) =6a(2) =266a(3) =22275a(4) =2757118a(5) =452329200a(6) =92484925445

External references