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 A033503 #9 Mar 27 2021 08:00:40
%S A033503 5,29,10,6,4,1,44,21,74,11,10,39,21,94,10,46,80,4,1,199,31,59,25,46,
%T A033503 59,45,50,35,55,25,21,109,10,1,30,25,25,4,16,39,1,20,49,25,181,109,70,
%U A033503 10,46,109,25,21,105,44,11,10,15,95,59,95,45,6,85,25,30,165,84,60,55,56
%N A033503 First differences of A046025.
%H A033503 Amiram Eldar, <a href="/A033503/b033503.txt">Table of n, a(n) for n = 1..10000</a>
%t A033503 Differences[Select[Range[3500],And@@PrimeQ[{6,12,18}#+1]&]] (* _Harvey P. Dale_, May 26 2014 *)
%Y A033503 Cf. A046025, A002997.
%K A033503 nonn
%O A033503 1,1
%A A033503 _Marc LeBrun_