Re: Summation problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg56663] Re: Summation problem*From*: Marcus Stollsteimer <marcus314 at yahoo.com>*Date*: Tue, 3 May 2005 05:26:15 -0400 (EDT)*Organization*: Comp.Center (RUS), U of Stuttgart, FRG*References*: <d4v6br$nq9$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

jaropis wrote: > Why can't Mathematica sum: > Sum[I^n/n,{n,1,Infinity}] > and gives the (incorrect) answer, that this is divergent while it > can do: Sum[I^(n+1)/n,{n,1,Infinity}] > correctly? seems to be a new feature in 5.1 ... In[1]:= Sum[I^n/n, {n, 1, Infinity}] Sum::div: Sum does not converge. Sum::div: Sum does not converge. n I Out[1]= Sum[--, {n, 1, Infinity}] n In[2]:= Sum[I^(n + 1)/n, {n, 1, Infinity}] Out[2]= -I Log[1 - I] In[3]:= $Version Out[3]= 5.1 for Linux (October 25, 2004) Regards, Marcus -- What is life but a series of inspired follies? -- George Bernard Shaw