There are (at least) two mathematical objects known as Weierstrass forms. The first is a general form into which an elliptic curve over any field K can be transformed, given by y^2 + a y = x^3 + b x^2 + c x y + d x + e, where a, b, c, d, and e are elements of K. The second is the definition of the gamma function as Γ(z) congruent [z e^(γ z) product_(r = 1)^∞(1 + z/r) e^(-z/r)]^(-1), where γ is the Euler-Mascheroni constant.

elliptic curve | gamma function

Karl Weierstrass