Expansion of e.g.f.: cos(log(1+x)^2).

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =-12a(5) =120a(6) =-1020a(7) =8820a(8) =-79548a(9) =746928a(10) =-7222560a(11) =70422000a(12) =-663291552a(13) =5383325376a(14) =-19385922192a(15) =-677619961200