Question 1210345
<pre>

Ikleyn says:

To avoid misunderstanding, here is my correction to the post by Edwin, 
where he placed his solution for Geometric progression.
His last formula in his post should be


{{{S[10]}}} = {{{6*((3^10-1)/(3-1))}}} = {{{6*(59048/2)}}} = 6*29524 = 177144.

And if you'll notice, that's exactly what I had

{{{S[10]=6*expr((3^10-1)/(10-1))=6*expr((59049-1)/(9))=6*expr((59048)/(9))=6*29524=177144}}}

Parentheses are not necessary.

Edwin</pre>