Value of $\frac{1}{3!} - \frac{1}{6!} + \frac{1}{9!} - \frac{1}{12!} + \ldots$
32637
What is the sum of this series: $\displaystyle\sum_{n=0}^{\infty} \dfrac{a^n}{(3n)!}$
60411
Why is $\frac{987654321}{123456789} = 8.0000000729?!$
137027
Find the value of $\sum_{n=0}^\infty\frac{1}{9n^2+9n+2}$
46661
A binomial inequality with factorial fractions: $\left(1+\frac{1}{n}\right)^n<\frac{1}{0!}+\frac{1}{1!}+\frac{1}{2!}+...+\frac{1}{n!}$
68853
Is there any formula for the series $1 + \frac12 + \frac13 + \cdots + \frac 1 n = ?$
47072
Proving the inequality $\frac{9}4\ + \frac{3abc}4\ \ge ab+bc+ca$
7302
$\sum k! = 1! +2! +3! + \cdots + n!$ ,is there a generic formula for this?
5332
Find the value of $\sum_0^n \binom{n}{k} (-1)^k \frac{1}{k+1}$
27304
Proving $ 1+\frac{1}{4}+\frac{1}{9}+\cdots+\frac{1}{n^2}\leq 2-\frac{1}{n}$ for all $n\geq 2$ by induction
24202
The value of the trilogarithm at $\frac{1}{2}$
17172
Series $\frac{x^{3n}}{(3n)!} $ find sum using differentiation
112929
How do I prove $\frac 34\geq \frac{1}{n+1}+\frac {1}{n+2}+\frac{1}{n+3}+\cdots+\frac{1}{n+n}$
18814
Sum of the series $1+\frac{1\cdot 3}{6}+\frac{1\cdot3\cdot5}{6\cdot8}+\cdots$
69288
Number of real roots of $\sum_{k=0}^{n}\frac{x^{k}}{k!}=0$
91316
Sum of the series $\sum _{ r=1 }^{ \infty }{ \frac { { r }^{ 3 } }{ r! } } $
131561
Find the value of $\left[\frac{1}{\sqrt 2}+\frac{1}{ \sqrt 3}+......+\frac{1}{\sqrt {1000}}\right]$
106888
Factorial identity $n!=1+(1-1/1!)n+(1-1/1!+1/2!)n(n-1)+\cdots$