Add multiple cells(cells are in incremental of 9)

[Ashurk77]

Hi,
I want to add multiple cells.
this cells are in incremental of N number.

eg
a3+a8+a13+a18 and so on.....

actually this adding goes upto 52cells.
thus manual adding is not possible.

can I do this by formula...?

Thanks in advance.

[NBVC]

Try something like:

=SUMPRODUCT(--(MOD(ROW($A$3:$A$100)-ROW(A3),5)=0),$A$3:$A$100)

adjust the A3:A100 ranges to the outerbounds of your actual range.

[Ashurk77]

Many Thanks