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 A043036 #22 Sep 01 2025 23:44:03
%S A043036 1,11,101,111,121,131,141,151,161,171,181,191,1001,1111,1221,1331,
%T A043036 1441,1551,1661,1771,1881,1991,10001,10101,10201,10301,10401,10501,
%U A043036 10601,10701,10801,10901,11011,11111,11211,11311,11411,11511,11611,11711,11811,11911
%N A043036 Base 10 palindromes that start with 1.
%C A043036 Union of A222723 (palindromic primes starting with a digit 1) and A222724 (palindromic nonprime numbers starting with a digit 1). - _Jaroslav Krizek_, Mar 03 2013
%H A043036 Harvey P. Dale and Jaroslav Krizek, <a href="/A043036/b043036.txt">Table of n, a(n) for n = 1..2222</a> (first 1000 terms from Harvey P. Dale)
%t A043036 palQ[n_Integer, base_Integer] := Module[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; Select[Range[0, 20000], IntegerDigits[#][[1]] == 1 && palQ[#, 10] &] (* _T. D. Noe_, Mar 12 2013 *)
%Y A043036 Cf. A002113 (palindromes in base 10).
%K A043036 nonn,base,changed
%O A043036 1,2
%A A043036 _Clark Kimberling_