Pemantle R, Wilf HS. Counting Nondecreasing Integer Sequences that Lie Below a Barrier. Electron. J. Combin. [Internet]. 2009May11 [cited 2026Mar.16];16(1):R60. Available from: https://www.combinatorics.org/ojs/index.php/eljc/article/view/v16i1r60