Find the number of sequences a1,a2,…,a100 such that (i) There exists i∈{1,2,…,100} such that ai=3, and (ii) |ai−ai+1|≤1 for all 1≤i<100.
Problem
Source: 2015 Thailand October Camp Inequalities & Combinatorics Exam p2
Tags: inequalities, Sequence
Source: 2015 Thailand October Camp Inequalities & Combinatorics Exam p2
Tags: inequalities, Sequence
Find the number of sequences a1,a2,…,a100 such that (i) There exists i∈{1,2,…,100} such that ai=3, and (ii) |ai−ai+1|≤1 for all 1≤i<100.