a(n) = [x^(2*n)] Product_{k=0..n} 1/(1 - k*x)^2.

A384205

a(n) = [x^(2*n)] Product_{k=0..n} 1/(1 - k*x)^2.

Terms

    a(0) =1a(1) =3a(2) =201a(3) =40792a(4) =16904053a(5) =11861321255

External references