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 A132285 #17 Dec 26 2024 03:49:54
%S A132285 11,33,55,77,99,1001,1111,1221,1331,1441,1551,1661,1771,1881,1991,
%T A132285 3003,3113,3223,3333,3443,3553,3663,3773,3883,3993,5005,5115,5225,
%U A132285 5335,5445,5555,5665,5775,5885,5995,7007,7117,7227,7337,7447,7557,7667,7777,7887
%N A132285 Odd palindromes with an even number of digits.
%H A132285 Vincenzo Librandi, <a href="/A132285/b132285.txt">Table of n, a(n) for n = 1..555</a>
%F A132285 A005408 INTERSECT A001637 INTERSECT A002113. - _R. J. Mathar_, Aug 22 2007
%t A132285 monQ[n_]:=Module[{len=IntegerLength[n],idn=IntegerDigits[n]},EvenQ[ len] &&Take[idn,len/2]==Reverse[Take[idn,-len/2]]]; Select[Range[11,9999,2], monQ] (* _Harvey P. Dale_, Apr 18 2014 *)
%o A132285 (PARI) isok(n) = {if (n % 2 == 0, return (0)); d = digits(n); if (#d % 2 == 1, return (0)); for (i=1, #d/2, if (d[i] != d[#d-i+1], return (0));); return (1);} \\ _Michel Marcus_, Nov 05 2013
%Y A132285 Cf. A005408, A001637, A002113, A132286, A132288.
%K A132285 nonn,base
%O A132285 1,1
%A A132285 _Artur Jasinski_, Aug 16 2007