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

A383767

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

Terms

    a(0) =1a(1) =0a(2) =2a(3) =42a(4) =1152a(5) =40520a(6) =1751850a(7) =90087522a(8) =5376546560a(9) =365487900192

External references