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 A124489 #11 Mar 27 2020 09:02:49
%S A124489 77385,87675,320775,329175,509355,1137045,1447110,2623005,3310965,
%T A124489 3974880,4095000,4339335,5183220,6163815,6975780,9080190,9462285,
%U A124489 10957170,11139975,11148900,12382755,12796140,15514695,15917580
%N A124489 Numbers k such that 2*k-1, 4*k-1, 6*k-1, 8*k-1, 10*k-1 and 12*k-1 are primes.
%H A124489 Amiram Eldar, <a href="/A124489/b124489.txt">Table of n, a(n) for n = 1..10000</a>
%t A124489 Select[3*5*7*Range[160000], And @@ PrimeQ /@ ({2, 4, 6, 8, 10, 12}*# - 1) &] (* _Ray Chandler_, Nov 21 2006 *)
%t A124489 Select[Range[16*10^6],AllTrue[2*Range[6]#-1,PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Apr 19 2019 *)
%Y A124489 Cf. A124485-A124492.
%K A124489 nonn
%O A124489 1,1
%A A124489 _Artur Jasinski_, Nov 04 2006