Compute ArcTan(n Pi+ Pi/2 + O(1))

*To*: mathgroup at smc.vnet.net*Subject*: [mg95808] Compute ArcTan(n Pi+ Pi/2 + O(1))*From*: Francois at news.free.fr, Fayard at news.free.fr*Date*: Wed, 28 Jan 2009 06:27:08 -0500 (EST)

Hello, I'm new to Mathematica and I want to compute a serie expantion of ArcTan(n Pi + Pi/2 + O(1)) (The O is a big O and is taken when n goes to Infinity) I dont know how to input O(1) in Mathematica. For example O[n,Infinity]^0 simplifies to 1 which is not what I want. Thanks for the help. Francois