how to reference a list of unique cells from one worksheet to another

I have a workbook that contains two worksheets. (Msexcel 2016)

On the first sheet I have in col A a list (300+) of unique alpha and numeric values (one alpha and up to 4 numeric chars). i.e. L1234 This list is sorted.

Cell
A1 L051
A2 L052
A3 L1234
A4 L7000

and so on

This list can change i.e. new or deleted unique chars and is updated by a copy paste of new values from an external source.

On the second sheet, I wish to reference each cell sequentially on sheet 1 i.e. A1 and A2 and A3 and A4 etc which is the "key" for population of other data on sheet 2

For example

On sheet 2 cell A5 needs to always reference cell A1 on sheet 1

On sheet 2 cell A15 needs to always reference cell A2 on sheet 1

On sheet 2 cell A25 needs to always reference cell A3 on sheet 1

and so on up to 300 iterations.

On sheet 2 cells A5 and A15 and A25 etc will be 10 rows apart.

At present, on sheet 2 I use a data validation dropdown list (at cells A5 and A15 and A25 etc) on the cells in col A1 but if there are changes I may miss a change

Is there a formula that can be used in cells A5 and A15 and A25 etc that will reference cells on sheet 1 A1 / A2 /A3 etc to ensure I dont miss any changes of this key data.

I thank you for your time and consideration.

Many thanks for a quick response.

I did have a look at the OFFSET function (should have mentioned) but could not get satisfactory results.(hit a brick wall)

Any direction you can provide on how to use this formula would be greatly appreciated.

I think I have just resolved my issue. The formula I have also been using is: =INDEX(Sheet1!A:A,(ROW()-5)/10+1). This has worked! Thank you for your time and effort. Please close this thread.