Understanding Summation Notation for Beginners

[icystrike]

2008
Summation (-1)^{i} \frac{i^2+i+1}{i!}
i=1
I guess I am suppose to apply the summation rule

and i got (-1)^{i} \frac{n(n+1)(n+2)+3n}{3i!}

 

[CompuChip]

What summation rule are you talking about?
What is n in your final answer?
How can it depend on i anyway, if you are summing over that?

Please elaborate a bit more on how you wanted to solve the question.

 

[icystrike]

What summation rule are you talking about?
What is n in your final answer?
How can it depend on i anyway, if you are summing over that?

Please elaborate a bit more on how you wanted to solve the question.

n is 2008.

Im uncertain of the application of summation - factorial.

 

[Cyosis]

Could you answer CompuChip's first question? Secondly are you sure the sum is listed correctly, because when I plug it into mathematica it gives a pretty terrible result. Not something one new to summations would be expected to do.