You have clear regularity between columns to loop and columns to hide.
As your loop column index increases by 2 (A, C, E, G etc.), hide column increases by 58 columns.
Backslash operator in calculation gives you round down integer.
5 \ 2 = 2, which you can also rewrite like Application.RoundDown(5/ 2, 0), or Fix(5 / 2)
So, as loop column increases by 2, the result from that calculation will increase by 1.
-4, -7 in calculation are the adjustment for the hide column index.
I added the variable "myAdj", so you can do a step debug.