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 A083836 #10 Jun 15 2018 18:56:38
%S A083836 7,55,595,727,787,5995,59995,72127,72727,78187,78787,599995,5999995,
%T A083836 7212127,7218127,7272727,7278727,7812187,7818187,7872787,7878787,
%U A083836 59999995,599999995,721212127,721272127,721818127,721878127,727212727
%N A083836 Palindromes of the form 6n + 1 where n is also a palindrome. palindromes arising in A083835.
%t A083836 6#+1&/@Select[Range[12121*10^4],AllTrue[{#,6#+1},PalindromeQ]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 15 2018 *)
%Y A083836 Cf. A083829, A083830, A083832, A083834, A083835.
%K A083836 base,nonn
%O A083836 1,1
%A A083836 _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 09 2003
%E A083836 More terms from _Ray Chandler_, May 21 2003