SciPy

scipy.misc.factorialk

scipy.misc.factorialk(n, k, exact=True)[source]

n(!!...!) = multifactorial of order k k times

Parameters:

n : int

Calculate multifactorial. If n < 0, the return value is 0.

k : int

Order of multifactorial.

exact : bool, optional

If exact is set to True, calculate the answer exactly using integer arithmetic.

Returns:

val : int

Multi factorial of n.

Raises:

NotImplementedError

Raises when exact is False

Examples

>>> from scipy.special import factorialk
>>> factorialk(5, 1, exact=True)
120L
>>> factorialk(5, 3, exact=True)
10L

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scipy.misc.factorial2