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 A131695 #15 Aug 30 2017 15:16:46
%S A131695 1,0,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%T A131695 1,0,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,1,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,
%U A131695 1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1
%N A131695 a(n) = 0 iff 2*prime(n+1) = prime(n) + prime(n+2), otherwise a(n) = 1.
%H A131695 Antti Karttunen, <a href="/A131695/b131695.txt">Table of n, a(n) for n = 1..20000</a>
%H A131695 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F A131695 a(n) = A098726(n) - 2. - _Filip Zaludek_, Dec 16 2016
%t A131695 Table[Boole[2 Prime[n + 1] != Prime@ n + Prime[n + 2]], {n, 120}] (* _Michael De Vlieger_, Dec 17 2016 *)
%o A131695 (PARI) A131695(n) = ((2*prime(1+n)) != (prime(n)+prime(2+n))); \\ _Antti Karttunen_, Aug 30 2017
%Y A131695 Cf. A001223, A122535, A064113 (positions of zeros).
%K A131695 nonn
%O A131695 1,1
%A A131695 _Giovanni Teofilatto_, Sep 15 2007
%E A131695 Definition and values corrected, keyword:cons removed; _R. J. Mathar_, Apr 22 2010