MathDB
Positive integers representable as sum and difference of powers of 2

Source: Bulgarian Spring Tournament 2023 11.3

March 25, 2023
number theory

Problem Statement

A positive integer bb is called good if there exist positive integers 1=a1,a2,,a2023=b1=a_1, a_2, \ldots, a_{2023}=b such that ai+1ai=2i|a_{i+1}-a_i|=2^i. Find the number of the good integers.