in reply to
A script to determine the next number in a sequence
Can't help you with the script suggestions but it is a nice idea.
I think I have the answer and I don't think this is a REAL numbers problem. 1, 5, 10, 25 and 50 are all U.S. currency coins. The next coin in sequence would be the 1 dollar coin which == 100. So the next number would be 100.
I could be wrong but I see no relations between the numbers otherwise.
"Age is nothing more than an inaccurate number bestowed upon us at birth as just another means for others to judge and classify us"