Definition:Binomial Coefficient/Notation

Definition

The notation $\dbinom n k$ for the binomial coefficient was introduced by Andreas Freiherr von Ettingshausen in his $1826$ work Die kombinatorische Analysis, als Vorbereitungslehre zum Studium der theoretischen höheren Mathematik.

It appears to have become the de facto standard in recent years.

As a result, $\dbinom n k$ is frequently voiced the binomial coefficient $n$ over $k$.

Other notations include:

$C \left({n, k}\right)$
${}^n C_k$
${}_n C_k$
$C^n_k$
${C_n}^k$

all of which can cause a certain degree of confusion.