This is under the binomial theorem. A binomial theorem is an equation that predicts the sequence when a binomial is raised to certain power. The general form of the equation is (a+b)^n. The equation for the binomial theorem would be
nCk a^(n-k) b^k, where k is the kth term of the expanded form, n is the nth power. The coefficient of the term in the binomial expansion is nCk or n!/k!(n-k)!.
