Re: Incorrect Summation

*To*: mathgroup at smc.vnet.net*Subject*: [mg129200] Re: Incorrect Summation*From*: amzoti <amzoti at gmail.com>*Date*: Thu, 20 Dec 2012 03:27:31 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20121218073534.C7529694B@smc.vnet.net> <kas30a$ciq$1@smc.vnet.net>

On Wednesday, December 19, 2012 1:56:26 AM UTC-8, Murray Eisenberg wrote: > What did you type, exactly, for Wolfram|Alpha? I tried several "obvious" things, e.g., > > sum cos(log(log(k)))/log(k) for k from 2 to infinity > > but WA was unable even to interpret it correct as asking for the sum of an infinite series. > > On Dec 18, 2012, at 2:35 AM, amzoti <amzoti at gmail.com> wrote: > > > Hi All, > > > can someone try this and see if it returns an incorrect result? > > > Sum[Cos[Log[Log[k]]]/Log[k],{k,2,Infinity}] > > > I tried it on WA and believe the result is incorrect. > > > Thanks. > --- > > Murray Eisenberg murray at math.umass.edu > > Mathematics & Statistics Dept. > > Lederle Graduate Research Tower phone 413 549-1020 (H) > > University of Massachusetts 413 545-2838 (W) > > 710 North Pleasant Street fax 413 545-1801 > > Amherst, MA 01003-9305 Just copy and paste the expression as-is: Sum[Cos[Log[Log[k]]]/Log[k],{k,2,Infinity}] For this example, if you increase the number of points to max on WA, you can see where I think the result is going astray and why this is returning an incorrect result. Aside: It is odd that sometimes WA accepts the user inputs in standard notation, but other times, it seems to get confused. I would think that if a user knows how to type Mathematica standard syntax correctly, that WA should be able to accept it. Thanks -A

**References**:**Incorrect Summation***From:*amzoti <amzoti@gmail.com>