Hello!!

I am new at work and my task is to continue what my predessor was doing.

He was working on a number generation algorithm and use to produce code numbers like 1031082728, 1041072728, 2202297820,2302287820

Now he has left us without leaving a trace of what he did to produce this code, I was wondering , is there way to understand what is common between this numbers? Is there any program to undo this?