Increase Linked Cell Formula

How can I increase a cells forumula reference cell by 30 each time it's dragged down.
For example
=('Santee EMC'!$A1) is in A1 on Summary Page
=('Santee EMC'!$A31) is in A2 on Summary Page
=('Santee EMC'!$A61) is in A3 on Summary Page.

etc..

I have been pulling my hair out over this all night and know it's something simple! Help?

I know somebody will come along with something smarter, but this is all I can think of right now.

=INDIRECT("'"&$C$1&"'!$A"&B1)

B1 = 1
B2 =B1+30
drag down

C1 = Santee EMC

Hi Nunzii,
In A1 put

=('Santee EMC!$A" &(ROW()-1)*30+1

and drag down.

I've been writing code all day so the above may not work in a formula.

In A1 the (ROW()-1)*30+1 will give the 1,31,61 etc
Then you may assemble the numbers along with the Santee EMC!$A
and then do an indirect. of the appended string.