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 A089183 #7 Mar 30 2012 17:34:13
%S A089183 1,11,101,1001,10201,102201,1023201,10233201,102313201,1023113201,
%T A089183 10231013201,102310013201,1023102013201,10231022013201,
%U A089183 102310232013201,1023102332013201,10231023132013201,102310231132013201
%N A089183 Palindromes in which, in the first half of the number, digits appear in the order 1, 0, 2, 3, 1, 0, 2, 3, 1, ...
%C A089183 A method of altering the order in the digit sets of palindromic numbers and making continued fractions from them.
%F A089183 c[1]=1 c[2]=0 c[3]=2 c[0]=3 a[m] = Delete[Table[If [ Floor[m/2]-n>=0, c[ Mod[n, 4]], c[Mod[m-n, 4]]], {n, 1, m}], m] b[m]=Sum[a[m][[i]]*10^(i-1), {i, 1, m-1}]
%t A089183 digits=50 c={1, 0, 2, 3} a[m_]=Delete[Table[If [ Floor[m/2]-n>=0, c[[ Mod[n, 4]]], c[[Mod[m-n, 4]]]], {n, 1, m}], m] b=Table[Sum[a[m][[i]]*10^(i-1), {i, 1, m-1}], {m, 2, digits}]
%Y A089183 Cf. A007907.
%K A089183 nonn,base
%O A089183 1,2
%A A089183 _Roger L. Bagula_, Dec 07 2003
%E A089183 Edited by _N. J. A. Sloane_, Jan 05 2009.