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 A068046 #31 Aug 10 2025 17:01:37
%S A068046 141,535,979,323,46264,626,33,383,88,939,3993,99,494,44,8998,99,11,
%T A068046 808,32823,282,66,44,55,505,22,535,848,11,111,11,11,55,555,55,6446,44,
%U A068046 22,303,44,88,5665,66,33,44,33,19091,909,66,454,66,33,393,141,27372,737,0,660,66,606,55,88,88,282,292,171,0
%N A068046 Palindromes of length greater than 1 in decimal expansion of Pi (not showing leading 0's).
%C A068046 The n-th palindrome starts at A068047(n) and has length A068048(n).
%C A068046 Is this sequence well-defined? For example, how do we know that 141... is not the start of the some very long palindrome in Pi? - _Sean A. Irvine_, Jan 19 2024
%H A068046 Alois P. Heinz, <a href="/A068046/b068046.txt">Table of n, a(n) for n = 1..10000</a>
%e A068046 Pi = 3.141592653589793238462643383279502884197169399375 ...
%e A068046 a(2) = 535, as the second nontrivial palindrome in Pi is '535', starting at A068047(2) = 9 with length A068048(2) = 3.
%t A068046 pi = RealDigits[ Pi, 10, 600][[1]]; palQ[n_] := n == Reverse[n]; k = 1; lst = {}; While[j = k + 1; k < 600, While[j < 600 - k, If[ palQ[ Take[pi, {k, j}]], p = FromDigits[ Take[ pi, {k, j}]]; AppendTo[ lst, p]; Print[p]]; j++]; k++]; lst (* _Robert G. Wilson v_, Jun 11 2013 *)
%Y A068046 Cf. A000796, A068047, A068048.
%K A068046 nonn,look,base
%O A068046 1,1
%A A068046 _Reinhard Zumkeller_, Feb 11 2002