Runs of Digits in Pi
Mathematica, 85 bytes

FromDigits/@DeleteDuplicatesBy[Join@@Subsets/@Split@RealDigits[Pi,10,#][[1]],Length]&amp;


Anonymous function. Takes n as input, and returns the elements of the sequence in the first n digits of &pi;. Output is in the form of {0, 3, 33, 111, ...}.