Feng Qi. Derivatives of tangent function and tangent numbers. Applied Mathematics and Computation, 268:844-858, 2015. [doi]
@article{Qi15, title = {Derivatives of tangent function and tangent numbers}, author = {Feng Qi}, year = {2015}, doi = {10.1016/j.amc.2015.06.123}, url = {http://dx.doi.org/10.1016/j.amc.2015.06.123}, researchr = {https://researchr.org/publication/Qi15}, cites = {0}, citedby = {0}, journal = {Applied Mathematics and Computation}, volume = {268}, pages = {844-858}, }