Number sequences

I have a simple sheet in which column A contains a series of formulas. Cell A1 contains the value '1' and cells A2 contains "+A1+1" and A3 contains "+A2+1" and so on. The result being I have a series of numbers in column A from 1 to 1000.

However when, for example, I delete the row that contains the value '23', the next and indeed the rest of the rows contain a #REF message. I need the formula in the new row 23 to refer to row 22, instead it still tries to refer to the row that has been deleted

I want to able to delete rows whist maintaining the numbering sequence (like the row headers do). I'd rather not go into VBA but if something like a Worksheet Change event is the only option, can anyone give me any clues.

A small problem but difficult to explain.

cheers

Richie