Given $a, b$, how do we find the number of distinct sums we can get from the range $[a,b]$?
14687
Is it possible to easily count all the possible distinct sums from distinct numbers?
119552
Summing Finitely Many Terms of Harmonic Series: $\sum_{k=a}^{b} \frac{1}{k}$
8990
In how many ways can a number be expressed as a sum of consecutive numbers?
138081
How to determine whether a number can be written as a sum of two squares?
77510
$\sum_{1}^{n}\left ( a_{i}b_{i} \right )\geq \prod_{1}^{n}\left ( a_{i}^{b_{i}} \right )$
104309
Pigeon-Hole Principle Common Sum
89512
Finding two numbers given their sum and their product
126304
Determining bounds for the sum $\sum\limits_{n=1}^\infty \frac{1}{2^n - 3^n }$
70827
Prove that $\sum_{i = n - b}^{a - m} {a - i \choose m}{b + i \choose n} = {a + b + 1 \choose m + n + 1}$
150430
Let $S={1, 2, 3, 4, ....., 2070}$ find the number of subsets of $S$ whose sum of elements in $S$ is divisible by 9
40080
Sum of multiples of $2$ coprime numbers cover positive integers
86051
Find the sum of reciprocals of divisors given the sum of divisors
98082
Another combinatorics problem: $\sum\limits_{k = 0}^n (-1)^k \binom{2n-k}k2^{2n-2k}=2n+1$
112253
How to find sums like $\sum_{k=0}^{39} \binom{200}{5k}$
129920
Is there any formula for number of divisors of $a \times b$?
149010
Finding Combinations to the provided Sum value
70677
Finite Sum of Power?