Adding error handling into an array formula that finds row numbers of a matching value

[D.Lovell]

Hi,

I need to have a cell on a worksheet where a value can be entered to check if it exists in column A. I need to then return all the row numbers where that value exists, it may be there multiple times and if so I need to list all the row numbers.

So far I have used this array formula:

{=SMALL(IF($A$2:$A$8=$I$2,ROW($A$2:$A$8)),ROW(1:1))}

Copied down a number of rows is does return the results I want, but then also returns the #NUM! error for additional rows where there are no more of the value I am checking for. I want the additional rows to remain blank and am struggling with this part. If the value entered to check doesn't exist at all, then all rows should remain blank.

Please can someone help with modifying this formula appropriately.

I have attached a small example which hopefully makes it clear what I mean.

Many thanks