Denominators in expansion of (exp(x)-1)^3.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =4a(7) =120a(8) =160a(9) =12096a(10) =20160a(11) =604800a(12) =403200a(13) =456192a(14) =5322240a(15) =217945728000a(16) =581188608000a(17) =139485265920a(18) =232475443200