The Thue-Morse sequence is a binary sequence satisfying:
The first several terms of are given as follows:
We define as the sorted sequence of integers such that the binary expression of each element appears as a subsequence in .
For example, the decimal number is expressed as in binary. appears in ( to ), so is an element of .
The decimal number is expressed as in binary. never appears in , so is not an element of .
The first several terms of are given as follows:
We can also verify that and .
Find the last digits of .
Write-up coming later
The complete problem is available here. An approach, code, and answer will be added later.