How to apply conditional formatting to rows multiple of an array of numbers

Question

I am trying to apply a conditional formatting rule to an array of rows, to start with row 11 and then apply to every 11+7x rows. I thought I could work with something like:

=MOD(row(), [11+7x])=0

but I can't figure it out.

1.
2.
3.
...
11. (Conditional Formatting)
12.
13.
...
18. (Conditional Formatting)
...
25. (Conditional Formatting)

Answer 1

Please try:

=MOD(ROW(),7)=4  

for Format values where this formula is true: under Use a formula to determine which cells to format (or Custom formula is) and Applies to (or Range:)

=$A$11:$A$x  (or A11:Ax)

where x is the limit of the range you wish this to apply to.