Chet,

For a list starting in cell A1, you could use something like

=IF((VALUE(RIGHT(A2,5))-1)=VALUE(RIGHT(A1,5)),"","Skipped")

copied down to match your list of SORTED serial numbers.

This assumes that your numbers of interest are the 5 right-most digits.

HTH,
Bernie
MS Excel MVP


"Chet-a-roo" wrote in message
...
I have a large list of serial numbers like (1AW15648). I need to identify
numbers that are missing.

Thanks,

Chet Sheetz

PS I am using Excel 2003