When i drag a formula down a column in excel it does not stay
consistant. I've inputted the following into Cells A100 - A102

in Cell A100: =A1
in Cell A101 = A5
in Cell A102 = A9

When i drag this formula down, i expect Cell A103 to reflect: =A13

However, it actually reflects: =A4

I understand why it is doing this, but how can i make it so the
formula stays consistant?
Cell A103 should reflect: =A13
Cell A104 should reflect: =A17
Cell A105 should reflect: =A21

Any help is appreciated

Thank you,

Jason