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 A031505 #13 Feb 02 2023 19:12:36
%S A031505 11,17,23,41,47,71,83,101,107,113,131,167,197,227,233,281,311,317,353,
%T A031505 383,401,443,461,467,491,503,617,647,677,743,761,773,827,857,863,881,
%U A031505 887,911,941,971,1013,1091,1097,1217,1283,1301,1307,1427,1433,1451
%N A031505 Upper prime of a difference of 4 between consecutive primes.
%H A031505 Harvey P. Dale, <a href="/A031505/b031505.txt">Table of n, a(n) for n = 1..1000</a>
%F A031505 a(n) = A029710(n-1) + 4 = A029708(n) + 2.
%p A031505 for i from 1 to 232 do if ithprime(i+1) = ithprime(i) + 4 then print({ithprime(i+1)}); fi; od; # _Zerinvary Lajos_, Mar 19 2007
%t A031505 Select[Partition[Prime[Range[250]],2,1],#[[2]]-#[[1]]==4&][[All,2]] (* _Harvey P. Dale_, Feb 02 2023 *)
%Y A031505 Essentially the same as A046132.
%K A031505 nonn
%O A031505 1,1
%A A031505 _Jeff Burch_
%E A031505 Corrected and extended by _Henry Bottomley_, Jul 18 2000
%E A031505 Definition clarified by _Harvey P. Dale_, Feb 02 2023