Create sequential numbers

[ChrisSlinko]

I would like to create sequential numbers automatically without the use of the field calculator.  I have a point feature class with a column that has sequential numbers when I go to add a point I would like it to calculate or add  the next number in the sequence. I would like to do this without using python or field calculator.  Any help would be appreciated.  Thank you in advanced.

[JoeBorgione]

I know of two approaches:

Attribute Assistant-  Attribute Assistant | ArcGIS Solutions 

and

Attribute Rules  Introduction to attribute rules—Geodatabases | Documentation 

The former is somewhat dated while the latter is here for the long haul.