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 A046276 #20 Oct 10 2019 00:33:52
%S A046276 1,1,2,6,4,2,7,5,4,88,88,99,9,22,87178,767,898,55,737,121,66,909,7777,
%T A046276 25852,484,1551,66,8888,888,93739,848,82228,353,881188,414,6666,999,
%U A046276 59795,1111,99,69596,61316,4260624,383,8448,7337,89498,979,67776,828
%N A046276 Largest palindromic substring in n! without an initial zero.
%H A046276 T. D. Noe, <a href="/A046276/b046276.txt">Table of n, a(n) for n = 0..300</a>
%e A046276 14! = {87178}291200.
%t A046276 isPal[d_List] := d[[1]] != 0 && d == Reverse[d]; Table[d = IntegerDigits[n!]; k = Length[d]; While[s = Select[Partition[d, k, 1], isPal]; s == {}, k--]; Max[FromDigits /@ s], {n, 0, 100}] (* _T. D. Noe_, Mar 25 2011 *)
%Y A046276 Cf. A046277.
%K A046276 nonn,base
%O A046276 0,3
%A A046276 _Patrick De Geest_, Jun 15 1998
%E A046276 Corrected by _D. S. McNeil_, Dec 10 2010