Mansour, Toufik, and Alek Vainshtein. “Restricted Permutations, Continued Fractions, and Chebyshev Polynomials”. The Electronic Journal of Combinatorics 7, no. 1 (February 27, 2000): R17. Accessed March 16, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v7i1r17.