def prod(seq):
    """Product of a sequence of numbers.

    Parameters
    ----------
    seq : sequence
        A sequence of numbers.

    Returns
    -------
    float or int
        Product of numbers.

    Notes
    -----
    This is defined as:

    .. math::

        \\prod_{i=1}^n x_i
    """
    mult = 1
    for x in seq:
        mult *= x
    return mult
