Hello I have found a pretty complicated way of finding the sum to this series, and was wondering if anyone could help me to find a simpler way.
The sum of the series 1+2+3+4+....+n= n(n+1)/2
What is the sum of 2+6+20+....+n(n+1)=???
If you are looking for sum of series:
then its:
You need to look for:
Look at this post:
http://www.mathhelpforum.com/math-he...1-2-3-4-a.html