Hypergeometric2F1 gives wrong complex infinities

*To*: mathgroup at smc.vnet.net*Subject*: [mg100868] Hypergeometric2F1 gives wrong complex infinities*From*: Wieland Brendel <wielandbrendel at gmx.net>*Date*: Tue, 16 Jun 2009 21:54:26 -0400 (EDT)

Dear all! I currently have a problem with the hypergeometric function: Consider Hypergeometric2F1[1, I, I + 1, -Exp[a]] Whenever I set a > 36 I only get "complex infinity" as a result although it should be perfectly finite (take 10 as a scale). Is there any way to expand the range of a to higher values? I would be very thankful for a solution! A big thanks in advance and best greetings from germany! Wieland Brendel PS: I use Mathematica 7.