write a record and increase the number in a field by one

I have a field in a table that started off with 1.  Each added record to the object I want to increase by 1.  How can I auto increase by 1.  It cannot be the autonumber field as I used it for a unique name.

Hi Bill!

Could you create a Ui-Only formula (number) field which has a formula:

{{$Model.YOURTABLEMODELNAME.data.length}} + 1
and then use a global action to create the record in the table and use the above Ui-Only field as a default value for the field in question?

Just a thought - not tested.

I would push on the AutoNumber features in the database.  I don’t really understand what you mean by needing a Unique name.  The SFDC setup allows you to specify a prefix to your autonumber - is that not unique enough?  

Otherwise the solution Louis provided is a good one.