Google Sheets – How to Sum Every 9th Row Starting from 4th Row

I have a column where there is a number every 9th row. The problem is that my first value starts on 4th row then all the next ones every 9th row. So far I tried this:

=ArrayFormula(sum(if(mod(row(J:J),9)=0,J:J))) => sum on J column every 9th row

and this:

=ArrayFormula(sum(if(mod(row(J4:J),9)=0,J4:J))) => I thought it would work but gives me the same result as the first one.

Is there a way to start from a row then sum every a number of row in Google Spreadsheets?