In algorithmic challenges you may very often meet problems that are somehow related to mathematical series, distributions, or combinatorics. As I not always remeber all the formulas I have created a quick reference.
1. Arithmetic Progression and Series
b) N-th element of the progression
Where r stands for the difference
2. Geometric Progression and Series
b) N-th element of progression
Where r stands for ratio.
3. Gauss sum
4. Gauss series
5. Sum of squares
6. Factorials sum
7. Binomial theorem
8. Harmonic function
In the next article we will summarise probability.