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 A222723 #7 Mar 14 2018 13:39:50 %S A222723 11,101,131,151,181,191,10301,10501,10601,11311,11411,12421,12721, %T A222723 12821,13331,13831,13931,14341,14741,15451,15551,16061,16361,16561, %U A222723 16661,17471,17971,18181,18481,19391,19891,19991,1003001,1008001,1022201,1028201,1035301,1043401 %N A222723 Palindromic primes starting with a digit 1. %C A222723 Subsequence of A002385 (palindromic primes) and A002113 (palindromic numbers). Complement of A222724 (palindromic nonprime numbers starting with a digit 1) with respect to A043036 (palindromic numbers starting with a digit 1). %H A222723 Jaroslav Krizek, <a href="/A222723/b222723.txt">Table of n, a(n) for n = 1..1000</a> %t A222723 Select[Prime[Range[85000]],PalindromeQ[#]&&IntegerDigits[#][[1]]==1&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Mar 14 2018 *) %Y A222723 Cf. A002385, A002113, A222724, A043036. %K A222723 nonn,base %O A222723 1,1 %A A222723 _Jaroslav Krizek_, Mar 03 2013