Monday, August 14, 2017

algebra precalculus - What is the term for a factorial type operation, but with summation instead of products?

(Pardon if this seems a bit beginner, this is my first post in math - trying to improve my knowledge while tackling Project Euler problems)



I'm aware of Sigma notation, but is there a function/name for e.g.



$$ 4 + 3 + 2 + 1 \longrightarrow 10 ,$$



similar to $$4! = 4 \cdot 3 \cdot 2 \cdot 1 ,$$ which uses multiplication?



Edit: I found what I was looking for, but is there a name for this type of summation?

No comments:

Post a Comment

analysis - Injection, making bijection

I have injection $f \colon A \rightarrow B$ and I want to get bijection. Can I just resting codomain to $f(A)$? I know that every function i...