Give a closed expression for the infinite sum:
1/1 + 2/(2+3) + 3/(4+5+6) + 4/(7+8+9+10) + ...
(In reply to Solution
by Nick Hobson)
> It strikes me this last step is
> quite difficult for a level 3, so
> I suspect Federico may have another
> solution up his sleeve!
Right you are! :-)