Counting & ProbabilityChallengeRecursion, Catalan Numbers & Generating Functions ShareRecursion, Catalan Numbers & Generating Functions · Challenge problemHow many sequences (a1,a2,…,a10)(a_1,a_2,\dots,a_{10})(a1,a2,…,a10) with every ai∈{1,2,3,4}a_i\in\{1,2,3,4\}ai∈{1,2,3,4} satisfy ∣ai+1−ai∣≤1|a_{i+1}-a_i|\le1∣ai+1−ai∣≤1 for i=1,2,…,9i=1,2,\dots,9i=1,2,…,9?Check Show answer Walk through it step by step Practice more like this Review this concept