Spouge's_approximation (Wiki).
Lanczos_approximation (Wiki).
Proof of the Euler product formula for the Riemann zeta function (Wiki).
Birds and Frogs (Freeman Dyson's article).
Wolstenholme's theorem (Wiki).
Lenstra elliptic curve factorization (Wiki).
Lambert W function (Wiki).
Arithmetic derivative (Wiki).
Cartessian Genetic Programming (pdf).
Cartessian Genetic Programming.
Cartessian Genetic Programming (resources).
Hardy&Littlewood circle method (Wiki).
Dedekind eta function (Wiki).
Modular form (Wiki).
Modular_group (Wiki).
Wallis product (Wiki).
Proof_by_infinite_descent: Irrationality of sqrt(2) (Wiki).