arithmetic sequence with Rows function

Hello, I am trying to figure out how to write my formula with Rows function to add 12 rows to the formula when dragging down.
e.g. =INDIRECT("Gantt!$B$12") I need to change to INDIRECT("Gantt!$B$24") next B36, B48 etc..
I understand this should work =Rows(A$4:A12)*$C$1 with my incremental difference of 12 being in C1.
But I don't understand how to combine the two formulas.
thanks

So, If I understand what you said:
=Rows(A$4:A12)*$C$1 will return the row number you want (12,36,48...)
So: =Indirect("Gantt!" & Rows(A$4:A12)*$C$1)

Try this ...

=INDIRECT("Gantt!B"&ROWS($A$1:A1)*$C$1)

Or:

=INDEX(Gantt!B:B,ROWS($A$1:A1)*$C$1)

CrimeDog, I get a #ref error with that one.

=Indirect("Gantt!B"&ROWS($A$1:A1)*$C$1) is getting me the output I need.
thanks very much

Just add 3 onto the end of the formula:

=INDIRECT("Gantt!D"&ROWS($F$3:F4)*$G$1+3)

Hope this helps.

Pete

Simple solution.
Thanks very much.

Glad to help - thanks for the rep.

Pete