Expansion of e.g.f (exp(x)-1)*(exp(2*x)-1).

Terms

a(0) =0a(1) =0a(2) =4a(3) =18a(4) =64a(5) =210a(6) =664a(7) =2058a(8) =6304a(9) =19170a(10) =58024a(11) =175098a(12) =527344a(13) =1586130a(14) =4766584a(15) =14316138a(16) =42981184a(17) =129009090a(18) =387158344a(19) =1161737178a(20) =3485735824a(21) =10458256050a(22) =31376865304a(23) =94134790218a(24) =282412759264a(25) =847255055010