How I come out of this logic?

Question

6. 5.
5. 8
4. 9

3. 10
2. 11
1. 12
How I come out of this logic means if I write 1 ,12 will be printed if I write 2 11 will be printed if I write 3. 10will be printed if I write 4. 9 will be printed and so on like this

Answer 1

Ok I think I interpreted it correctly. In python:
x = 12-(x-1)%12+(x-1)//12*12

And to test:
arr = [(x, 12-(x-1)%12+(x-1)//12*12) for x in range(1,37)]
print(arr)

Answer 2

But that not fit on mah logice when I come to the n terms like this
18. 19
17. 20
16. 21

15. 22
14. 23
13. 24
And so on on series like this

Answer 3

Then it must be a more complex equation that simplifies to 13-x for 1-12 like Odex 🇮🇹 said.

Can you please write all expected values for 1-30 (at least)?