New posts in summation

Prove using the method of double counting: $3^n =\sum_{k=0}^n \dbinom{n}{k} \sum_{j=0}^k \dbinom{k}{j}$ [duplicate]

Is there a closed-form of $\frac{\zeta (2)}{\pi ^2}+\frac{\zeta (4)}{\pi ^4}+\frac{\zeta (6)}{\pi ^6}+.....$

$\sum_{n=-\infty}^\infty e^{-\alpha n^2+\beta n}$

Summation inductional proof: $\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+\ldots+\frac{1}{n^2}<2$ [duplicate]

Relation between $\gcd$ and Euler's totient function .

Finding $\sum \frac{1}{n^2+7n+9}$

Can we assign a value to the sum of the reciprocals of the natural numbers?

Is there a metric in which 1+2+3+4+... converges to -1/12?

Double summation, index change clarification.

Proving that $1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\cdots+\frac{1}{2n-1}-\frac{1}{2n}=\frac{1}{n+1}+\frac{1}{n+2}+\cdots+\frac{1}{2n}$

Formula for finite power series

Arithmetic pattern $1 + 2 = 3$, $4 + 5 + 6 = 7 + 8$, and so on

How to prove the sum of combination is equal to $2^n - 1$

Fractional part summation

A tough integral $\int_0^{\infty}\frac{\operatorname{sech}(\pi x)}{1+4x^2}\, \mathrm dx $

Computig the series $\sum\limits_{n=2}^\infty \ln\left(1-\frac{1}{n^2}\right)$

Using the rules that prove the sum of all natural numbers is $-\frac{1}{12}$, how can you prove that the harmonic series diverges?

How would I express the series $|1+1+1|+|1+1-1|+|1-1+1|+|1-1-1|+|-1+1+1|+|-1+1-1|+|-1-1+1|+|-1-1-1|$ in summation notation?

Has anyone heard of this maths formula and where can I find the proof to check my proof is correct? $\sum^n_{i = 1}i + \sum^{n-1}_{i=1}i = n^2$

Find the sum $\frac{1}{\sqrt{1}+\sqrt{2}} + \frac{1}{\sqrt{2}+\sqrt{3}} + ...+ \frac{1}{\sqrt{99}+\sqrt{100}}$