ramanujan ( x -- y )

Vocabulary

math.extras

Inputs

x

a number

Outputs

y

a number

Word description

Return the Ramanujan approximation of factorial(x).

Definition

USING: math math.constants math.functions ;

IN: math.extras

:: ramanujan ( x -- y )
    pi sqrt x e / x ^ * x 8 * 4 + x * 1 + x * 1/30 + 1/6 ^ * ;