Definition:Binomial Coefficient/Notation

Definition
The notation $\dbinom n k$ for the binomial coefficient was introduced by in his $1826$ work.

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

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.