Arithmetic Progression with cells?

Hi!
My question is : Is it possible to create a formula that would give the sum of cells that are in arithmetic progression in excel?

Example:
Let's first choose 4 cells that are in arithmetic progression, B14 , B20 , B26 and B32 for instance(the common difference here is 6). So what I want to do is: I want to type a formula in another cell, lets suppose C5, that will automatically give me the sum of the values of B14,B20,B26 and B32. I am aware that I can just type on C5 =B14+B20+B26+B32 but and if I wanted the sum of 90 cells??Wouldn't it be too much work to type all the cells? Does Anyone know a formula for it?

thanks! :]

If you have an arithmetic series in A1, A2, ..., then the sum of the first N terms in the series is

=N*(2*A1 + (N-1)*(A2-A1)) / 2

Their values are not in arithmetic series but they are.

I can't parse that.

Can you see that C30 is 5 rows away from C25 and C25 is also 5 rows away from C20?

Yes ... so?

C20 = 550
C25 = 10
C30 = 200

Dos that mean you want to sum 200 cells in column B, starting at B550, and adding every 10th cell?

OK; so what cells should be summed for that example?

Maybe like this:

Please Login or Register  to view this content.

Exactly like this!!
To be honest, I really didn't understand the formula you used to calculate it. But I understood how you did it.

I think that that solves my problem :D!
thank you very much for the help

PS: I'll try to use it right now.

You’re welcome. Would you please mark the thread as Solved?

Click the Edit button on your first post in the thread

Click Go Advanced, select [SOLVED] from the Prefix dropdown, then click Save Changes

Please don't quote whole posts -- it just clutters the forum.


I updated my last post to show the formula in D4.