Expansion of Product_{k=0..4} (1 + k*x)/(1 - k*x).

Terms

a(0) =1a(1) =20a(2) =200a(3) =1400a(4) =8000a(5) =40520a(6) =190400a(7) =852200a(8) =3692000a(9) =15640520a(10) =65225600a(11) =268985000a(12) =1100372000a(13) =4475152520a(14) =18122340800a(15) =73156029800a(16) =294627068000