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 A175813 #20 May 15 2025 11:26:07
%S A175813 84,576,578,580,582,646,654,682,684,686,688,690,692,694,696,698,700,
%T A175813 702,706,722,736,740,742,2406,2408,2414,2416,2430,2432,2438,2440,2502,
%U A175813 2504,2506,2512,2514,2516,2518,2522,2524,2540,2542,2546,2548,2756,2758,2762
%N A175813 Numbers m such that the first m decimal digits of Pi contain equal numbers of even and odd decimal digits.
%C A175813 Is this sequence infinite?
%H A175813 Pontus von Brömssen, <a href="/A175813/b175813.txt">Table of n, a(n) for n = 1..16886</a> (all terms below 10^9; terms 1..459 from Harvey P. Dale)
%e A175813 84 is in the sequence because the first 84 digits of Pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986 include 42 odd digits and 42 even digits.
%t A175813 L= Rest@FoldList[ Plus, 0, (-1)^First@ RealDigits[Pi, 10, 3000]] ;Do[If [L[[n]]==0,Print[n]],{n,3000}]
%t A175813 Position[Accumulate[If[EvenQ[#],1,-1]&/@(RealDigits[Pi,10,3000][[1]])],0]//Flatten (* _Harvey P. Dale_, Jan 10 2024 *)
%Y A175813 Cf. A175792.
%K A175813 nonn,base
%O A175813 1,1
%A A175813 _Michel Lagneau_, Sep 09 2010