Expansion of sin(tanh(x))/cos(x).A009526Expansion of sin(tanh(x))/cos(x).Terms a(0) =1a(1) =0a(2) =32a(3) =-280a(4) =27520a(5) =-1072896a(6) =137702528a(7) =-12544190464External referencesoeis: A009526