code: def sbessely(x, N):
      
  
      out = np.zeros(N, dtype=np.float64)
  
      out[0] = -np.cos(x) / x
      out[1] = -np.cos(x) / (x ** 2) - np.sin(x) / x
  
      for n in xrange(2, N):
          out[n] = ((2.0 * n - 1.0) / x) * out[n - 1] - out[n - 2]
  
      return out
docs: Returns a vector of spherical bessel functions yn:
  
          x:   The argument.
          N:   values of n will run from 0 to N-1.