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 A124487 #12 Mar 27 2020 09:01:44
%S A124487 3,45,705,945,5295,5775,5955,6450,8580,9945,11175,12120,13095,18000,
%T A124487 18525,18690,19710,22440,22785,24960,30390,33780,34335,37665,41790,
%U A124487 44460,52185,54180,56175,57300,63570,66990,67515,67725,73335,74700
%N A124487 Numbers k such that 2*k-1, 4*k-1, 6*k-1 and 8*k-1 are primes.
%H A124487 Amiram Eldar, <a href="/A124487/b124487.txt">Table of n, a(n) for n = 1..10000</a>
%t A124487 Select[Range[80000], And @@ PrimeQ /@ ({2, 4, 6, 8}*# - 1) &] (* _Ray Chandler_, Nov 21 2006 *)
%Y A124487 Cf. A124485-A124492.
%K A124487 nonn
%O A124487 1,1
%A A124487 _Artur Jasinski_, Nov 04 2006
%E A124487 Extended by _Ray Chandler_, Nov 21 2006