>>10218676This is the definition of the functions expanded over the basis of polynominal powers of x. You could also expand these functions over any other infinite orthogonal basis, like the legendre polynominals, hermite polynominals, bessel functions, etc. I want to say that you could expand them over any hypergeometric function, but I'm only a physics undergrad and lack the balls to make a claim that all hypergeometric functions form an orthogonal basis.
