Filling a column with a repeating pattern of numbers

Does anyone know how I would fill a column with a simple repeating pattern of numbers, for example, using 1,2,3 over and over again? It seems like something that autofill could do, but I can't seem to get it to work. I tried using Series, but it only displays the series once.

How do I get this to work? Sometimes I think Excel requires a blood sacrifice to get results.

Thanks, much appreciated.

Thanks, I got it.