Ramanujan Continued Fraction

Let $f(a,b)$ be a Ramanujan Theta Function. Then

$${f(-q,-q^4)\over f(-q^2,-q^3)} = {1\over 1+} {q\over 1+} {q^2\over 1+} {q^3\over 1+\ldots},$$

where the quantity on the right is a Continued Fraction.

See also Ramanujan Theta Functions