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 A099343 #7 Sep 20 2023 07:47:34
%S A099343 1,6,65,632,6228,62070,625563,6248822,62497832,624987694,6250055390,
%T A099343 62500266095
%N A099343 Frequency of the hexadecimal A in the first 10^n hexadecimal digits of Pi.
%H A099343 Kanada Laboratory, <a href="https://web.archive.org/web/20120324194210/http://pi2.cc.u-tokyo.ac.jp/pi-hexa_current.html">Statistical Distribution Information</a>.
%t A099343 $MaxPrecision = 1100000; ph = Drop[ RealDigits[Pi, 16, 5*10^5] [[1]], 1]; Table[ Count[ Take[ph, 10^n], 10], {n, 5}]
%Y A099343 Cf. A000796, A062964, A099333, A099334, A099335, A099336, A099337, A099338, A099339, A099340, A099341, A099342, A099344, A099345, A099346, A099347, A099348.
%K A099343 base,nonn,more
%O A099343 1,2
%A A099343 _Robert G. Wilson v_, Oct 12 2004