Mathematical plot twist: q-binomial coefficients

The simplest instance of a q-analog in math is to replace a positive integer n by a polynomial in q that converges to n as q → 1. Specifically, we associate with n the polynomial [n]q = 1 + q + q² + q³ + … + qn-1. which obviously converges to n when q → 1. […] The post Mathematical plot twist: q-binomial coefficients first appeared on John D. Cook....