def _Z(order):
    """
    Returns the constants for Yoshida Triple Jump.
    Used to compose higher order (even) integrators.

    References
    ----------
    .. [1] Yoshida, Haruo,
        "Construction of higher order symplectic integrators";
         Physics Letters A, vol. 150, no. 5-7, pp. 262-268, 1990.
        `DOI: <https://doi.org/10.1016/0375-9601(90)90092-3>`__

    """
    n = (order - 2) / 2
    x = 2 ** (1 / (2 * n + 1))
    Z0 = -x / (2 - x)
    Z1 = 1 / (2 - x)

    return Z0, Z1