New posts in combinatorics

Average number of strings with edit distance at most 4

probability combinatorics gap

$100$ boxes of fruits - pick $51$ and get at least half of each type?

combinatorics contest-math

A game played on graphs by "flipping" the state of a vertex and its neighbors

combinatorics graph-theory recreational-mathematics

On the impossibility of proving certain problems using double counting.

combinatorics reference-request contest-math

A problem about symmetric relations on finite sets.

combinatorics graph-theory algorithms recreational-mathematics relations

Problem about subsets of $\{1, 2,\dots,n\}$

combinatorics elementary-set-theory

When two voters meet, they switch allegiance; might they all ally with the same candidate?

combinatorics puzzle

Reciprocal binomial coefficient polynomial evaluation

combinatorics polynomials binomial-coefficients symmetric-polynomials

Why is Euler's totient function equal to $(p-1)(q-1)$ when $N=pq$ and $p$ and $q$ are prime in a clean intuitive way?

combinatorics number-theory cryptography totient-function

Definition of star in a simplicial complex

combinatorics algebraic-topology

Burnside's Lemma

combinatorics puzzle

Fractional oblongs in unit square via the Paulhus packing technique

sequences-and-series combinatorics mathematica packing-problem open-problem

Fibonacci cycles for finite groups

abstract-algebra combinatorics group-theory elementary-number-theory finite-groups

Bijection for $q$-binomial coefficient

combinatorics binomial-coefficients integer-partitions q-analogs

How many necklaces are there with a known number of beads of each color? [duplicate]

combinatorics polya-counting-theory necklace-and-bracelets

How many injective functions from $\{5,6,7,8,9\}$ to itself map $5$ and $6$ to another number?

combinatorics proof-verification relations

10 passengers in a boat

Asymptotic frequency of $[0,\,1,\,1]$ in the Thue–Morse sequence

sequences-and-series combinatorics number-theory asymptotics conjectures

Curious question about cardinality of finite sets

Can you provide a symmetric presentation of this partition lattice?

combinatorics lattice-orders