number of sequences of 2005 terms with terms 1 or -1
Source: Slovenia TST 2005 p4
February 15, 2020
combinatoricsSumSequencealgebra
Problem Statement
Find the number of sequences of terms with the following properties:
(i) No three consecutive terms of the sequence are equal,
(ii) Every term equals either or ,
(iii) The sum of all terms of the sequence is at least .