What is the best formula for make sequence rotation in excel/sheet?

I would like to know what is the best formula for make sequence rotation in excel/sheet.

For example, I have a dataset like this :

enter image description here

and I want to make the sequence rotation like this :

enter image description here

Thanks!

1 Answer

Try an if statement?

=IF(A1=1,15,A1-1)

If your data starts in a1, type that formula in b1, then drag the bottom corner of the formula to the right as far as you want. Then with all of the cells in row 1 highlighted, drag the bottom right hand corner of farthest right cell highlighted down.