This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A120584 #2 Mar 30 2012 17:26:21
%S A120584 33,5,16,11,6,20,8,1,2,21,41,11,46,61,14,19,82,32,18,49,105,50,11,37,
%T A120584 105,19,19,136,113,34,234,77,66,166,1,51,109,98,42,19,20,154,49,26,25,
%U A120584 44,111,93,46,40,265,77,69,182,421,286,154,9,3,24,64,22,61,69,85,21,28
%N A120584 Distance between n-1 and n in decimal expansion of Pi A000796.
%C A120584 a(0)=33 because position of first zero is 33; after this zero, "1" is at position 5, hence a(1)=5; after this 1, "2" is at position 16, hence a(2)=16; after this 2, "3" is at position 11, hence a(3)=11 etc.
%t A120584 ts=ToString[FromDigits[RealDigits[N[Pi,20000]][[1]]]]; Reap[Do[sp=StringPosition[ts,ToString[n]][[1,1]];Sow[sp];ts=StringDrop[ts,sp],{n,0,100}]][[2,1]]
%Y A120584 Cf. A000796.
%K A120584 base,nonn
%O A120584 0,1
%A A120584 _Zak Seidov_, Aug 17 2006