proof for the Ramanujan's formula ?
48363
Nested Radical of Ramanujan
117540
Proof of Dobinski's formula for Bell numbers
129860
Find a formula for this sequence (and prove it).
47596
An infinite series plus a continued fraction by Ramanujan
49294
prove that $\operatorname{lcm}(n,m) = nm/\gcd(n,m)$
102398
Help deriving that $\mathrm{sign} : S_n\to \{\pm 1\}$ is multiplicative
58264
How to derive the formula for the sum of the first $n$ perfect squares?
7003
Inductive proof of a formula for Fibonacci numbers
73238
Show that $a^{q-1} \equiv 1 \pmod{pq}$
145019
Prove that $\sum_{n=0}^\infty \frac{(-1)^n}{3n+1} = \frac{\pi}{3\sqrt{3}}+\frac{\log 2}{3}$
107924
Prove (or derive) the de Polignac formula for the prime decomposition of $n!$
139057
Showing that $\frac{1}{2\pi}\int^{2\pi}_{0}(2\cos\theta)^{2n}d\theta=\frac{(2n)!}{n!n!}$
25232
Is this formula for the $n^{th}$ prime number useful?
23093
Proof of recursion formula for Stirling number of the second kind
122490
Proof of Parseval's identity
49806
Prove that $\frac{R/ \ker \phi}{(\ker \phi + J)/ \ker \phi} \cong \frac{S}{\phi(J)}$
129801
Finding a closed form for $\sum^{n}_{k=1} \frac{k}{(k+1)!} $