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 A124520 #15 Dec 17 2019 07:39:24
%S A124520 3,30,33,63,75,78,93,102,123,138,153,162,165,192,195,240,252,273,297,
%T A124520 303,342,387,393,420,435,438,450,468,483,522,525,540,588,630,633,660,
%U A124520 663,717,738,747,750,765,798,825,837,855,957,978,993,1023,1032,1062
%N A124520 Numbers k such that 14*k - 1 and 14*k + 1 are twin primes.
%H A124520 Amiram Eldar, <a href="/A124520/b124520.txt">Table of n, a(n) for n = 1..10000</a>
%e A124520 3 is in the sequence since 14*3 - 1 = 41 and 14*3 + 1 = 43 are twin primes.
%t A124520 Select[Range[1100], And @@ PrimeQ[{-1, 1} + 14# ] &] (* _Ray Chandler_, Nov 16 2006 *)
%Y A124520 Cf. A040040, A045753, A002822, A124065, A124518, A124519, A124521, A124522, A063983.
%K A124520 nonn
%O A124520 1,1
%A A124520 _Artur Jasinski_, Nov 04 2006
%E A124520 Extended by _Ray Chandler_, Nov 16 2006