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 A135023 #5 Sep 17 2016 00:28:53
%S A135023 1,1,1,3,1,3,1,3,3,1,3,1,3,3,4,4,1,1,7,7,7,3,1,5,1,3,3,3,3,1,5,1,1,6,
%T A135023 6,6,6,1,3,1,5,3,3,3,1,3,1,5,7,7,7,1,7,7,7,3,5,1,3,4,4,3,3,3,4,4,4,4,
%U A135023 5,1,5,1,3,3,4,4,1,6,6,4,4,4,4,3,6,6,1,9,9,9,3,5,3,3,1,3,5,3,3,1,3,3,1,6,6
%N A135023 (NextPrime[6*n] - PreviousPrime[6*n])/2.
%C A135023 a(n)=1 if 6n -/+ 1 are twin primes.
%H A135023 G. C. Greubel, <a href="/A135023/b135023.txt">Table of n, a(n) for n = 1..1000</a>
%t A135023 Table[(NextPrime[6*n] - NextPrime[6*n, -1])/2, {n, 1, 25}] (* _G. C. Greubel_, Sep 17 2016 *)
%K A135023 nonn
%O A135023 1,4
%A A135023 _Zak Seidov_, Feb 10 2008