I agree it is a good puzzle.

However both the title , the increasing number of digits
in the 4 numbers given and the 3/14ate  just implied the correct answer.

In the "online tool " i.e " the 1st 100000 digits of pi" I've verified that 0 is the last digit to exhaust the ten decimal digits and then looked up tho good old SLOANE (OEIS)to get:

A032510

 Scan decimal expansion of Pi until all n-digit strings have been seen; a(n) is last string seen.  0, 68, 483, 6716, 33394, 569540, 1075656, 36432643, 172484538, 5918289042, 56377726040

Ans: 33394

Edited on March 24, 2014, 11:04 am

Posted by Ady TZIDON on 2014-03-24 10:55:10