Langford problem
Series: Linear Optimization
Who Betrayed Dune’s Duke Leto?
Series: Riddler Puzzles
Flowfree
Series: Linear Optimization
Riddle of the pilgrims
Series: Linear Optimization
Unusual Crossword
Problems for children from 5 to 15 by V.I. Arnold
A curious identity involving $e$ and $\pi$
Series: Infinite Series
Problems by Ramanujan
Problems in summation of series
Series: Infinite Series
&= \int \frac{1}{1-z}dz = -ln(1-z) \
\implies f(z) &= -\frac{ln(1-z)}{1-z} \end{align*} $$ Problem 2 Evaluate $\sum_{n=0}^{\infty} \frac{(-1)^n)}{3^n(2n + 1)}$.