Thread: Forcing row increment when draggin/copying a formula

I have the following formula in cell E11 on Sheet2
=SUM('SHEET1'!E11:E12))
When I drag drag/copy the formula down I want the rows to increment by 6
So cell E12 would have the following formula
=SUM('SHEET1'!E17:E18))
and so on....
I have not been able to figure out a way to force this *6 increment
Any ideas would be greatly appreciated.

The actual formula is =IF((SUM('INTERNAL USE CROWN MASTER COPY'!F26:F27))=0," ",(SUM('INTERNAL USE CROWN MASTER COPY'!F26:F27)))
I just cut it down above to simplify for the sake of the question.
Thank You