FindX - Sequence

This is a math sequence game.
The numbers seem not related to each other.

But there is a hide equation to link them.

You need to find out the relationship between the number in order to find out X.
Through solving the sequence, you will find some famous math sequence.

If you find it, please leave a comment to share. Thanks!



Background Music References:
Comfortable Mystery 2 - Film Noire by Kevin MacLeod is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/)
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100537
Artist: http://incompetech.com/