Finding the Sum of any Quadratic Sequence

I found myself googling sequences and series to find out how to solve this problem but couldn't find anything. So I proved this formula which I hope you can use to simplify difficult problems.

[mrwalletfat]

Great video, maybe next you could possibly elucidate topics on the hodge conjectures and abstract algebra such as, vector spaces and algebra over a field. Thank you.

[ceciliamoleko]

Greetings Sir. Isn't there any way that we can make a formula of finding the sum of a quadratic series that is more easier like the ones of arithmetic and geometric series?

[mrnub]

I am a O level student and i am currently facing this problem. I believe there is another way for this and i gave up and just used a calculator.

[dylanmacariola]

get a black whiteboard and neon markers and ill give a like