Bi⁡(-z)∼1π⁢z1/4⁢(-sin⁡(ζ-14⁢π)⁢∑k=0∞(-1)k⁢u2⁢kζ2⁢k+cos⁡(ζ-14⁢π)⁢∑k=0∞(-1)k⁢u2⁢k+1ζ2⁢k+1),