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 A154671 #15 Dec 17 2019 07:40:53
%S A154671 12,108,192,432,1452,2028,3468,4800,10092,18252,106032,139968,221952,
%T A154671 284592,299568,355008,549552,618348,720300,786432,823728,961068,
%U A154671 995328,1009200,1138368,1190700,1291008,1529388,1537968,1651692,1948908
%N A154671 Averages of twin prime pairs k such that k*3 and k/3 are squares.
%H A154671 Amiram Eldar, <a href="/A154671/b154671.txt">Table of n, a(n) for n = 1..10000</a>
%F A154671 a(n) = 12*A154331(n)^2. - _M. F. Hasler_, Jan 15 2009
%e A154671 12*3 = 36 = 6^2, 12/3 = 4 = 2^2.
%t A154671 lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1],s=(n*3)^(1/2); If[Floor[s]==s,AppendTo[lst,n]]],{n,6,10!,6}]; lst...and/or... lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1],s=(n/3)^(1/2); If[Floor[s]==s,AppendTo[lst,n]]],{n,6,10!,6}]; lst
%t A154671 Select[Mean/@Select[Partition[Prime[Range[150000]],2,1],#[[2]]-#[[1]] == 2&],AllTrue[{Sqrt[#/3],Sqrt[3#]},IntegerQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Dec 06 2015 *)
%o A154671 (PARI) for(i=1,999, isprime(12*i^2+1) && isprime(12*i^2-1) && print1(12*i^2",")) \\ _M. F. Hasler_, Jan 15 2009
%Y A154671 Cf. A154670.
%K A154671 nonn
%O A154671 1,1
%A A154671 _Vladimir Joseph Stephan Orlovsky_, Jan 13 2009