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 A123979 #17 Mar 27 2020 09:01:58
%S A123979 1,3,8,16,23,38,51,71,73,108,141,156,166,178,198,233,271,288,346,376,
%T A123979 451,453,471,478,646,656,773,778,786,871,926,1003,1013,1031,1156,1213,
%U A123979 1311,1338,1543,1576,1618,1696,1751,1776,1793,1846,1856,1921,1933,1963
%N A123979 Numbers k such that 12*k+1, 12*k+5 and 12*k+7 are primes.
%H A123979 Amiram Eldar, <a href="/A123979/b123979.txt">Table of n, a(n) for n = 1..10000</a>
%p A123979 a:=proc(n) if isprime(12*n+1)=true and isprime(12*n+5)=true and isprime(12*n+7)=true then n else fi end: seq(a(n),n=1..2800); # _Emeric Deutsch_, Nov 06 2006
%t A123979 Select[Range[2000], And @@ PrimeQ /@ ({1, 5, 7} + 12#) &] (* _Ray Chandler_, Nov 05 2006 *)
%Y A123979 Cf. A110801.
%K A123979 nonn
%O A123979 1,2
%A A123979 _Artur Jasinski_, Oct 30 2006
%E A123979 Extended by _Ray Chandler_, Nov 05 2006
%E A123979 More terms from _Emeric Deutsch_, Nov 06 2006