New posts in Additive Combinatorics

Two sets having the same subset sums.

How to show that $\gcd(a_1,a_2,\cdots,a_k) = 1$ implies that there exist a non-negative solution to $\sum_{i=1}^{n}a_ix_i = n$ for large $n.$

Compressing the primes using simple addition?

Sums of squares in characteristic 3

Combinatorial puzzle reminiscent of knapsack problem. Is this classic?

Sum of two squares modulo p

Special subdivision of numbers from 1 to 99

Quadratic sum of Gauss integers

Is each squared finite group trivial?

Converse to Erdős' conjecture on arithmetic progressions