Hadamard Factorization Theorem

Theorem
Let $f: \C \to \C$ be an entire function of finite order $\omega$.

Let $\left\langle{a_n}\right\rangle$ be the sequence of nonzero zeroes of $f$, repeated according to multiplicity.

Then $f$ has finite rank $p$ and there exists a polynomial $g$ of degree at most $\omega$ such that:
 * $\displaystyle f \left({z}\right) = e^{g(z)} \prod_{n \mathop = 1}^\infty E_p\left( \frac z{a_n} \right)$

where $E_p$ denotes the $p$th Weierstrass elementary factor.

Proof
By Convergence Exponent is Less Than Order, $f$ has finite rank.

Also see

 * Weierstrass Factorization Theorem