order of function to compute
x : float
    Argument at which to evaluate

Returns
-------
yn : ndarray
    Value of y0(x), ..., yn(x)
ynp : ndarray
    First derivative y0'(x), ..., yn'(x)

Notes
-----
The computation is carried out via ascending recurrence, using the
relation DLMF 10.51.1 [2]_.

Wrapper for a Fortran routine created by Shanjie Zhang and Jianming
Jin [1]_.

References
----------
.. [1] Zhang, Shanjie and Jin, Jianming. "Computation of Special
       Functions", John Wiley and Sons, 1996.
       https://people.sc.fsu.edu/~jburkardt/f77_src/special_functions/special_functions.html
.. [2] NIST Digital Library of Mathematical Functions.
       https://dlmf.nist.gov/10.51.E1

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