I can't find out a function f(x)=y that would map my x's to required y's. It is OK to write it in a programming language. Notation in mathematics is also OK.
It must be something simple enough but I can't find a solution.
X: >> Y:
1 1
2 1
3 2
4 2
5 4
6 4
7 8
8 8
9 16
10 16
...