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 A171386 #33 Sep 24 2015 12:02:38
%S A171386 0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T A171386 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A171386 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N A171386 The characteristic function of 2 and 3: 1 if n is prime such that either n-1 or n+1 is prime, else 0.
%C A171386 A181354(n) + A181376(n) + A181378(n) + A181380(n) + A181384(n) + A181401(n) + A181403(n) + A181405(n) + a(n) = A052268(n).
%H A171386 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).
%F A171386 a(n) = A130130(n) - A130130(n-1), for n>0.
%t A171386 Join[{0, 1, 1},LinearRecurrence[{1},{0},102]] (* _Ray Chandler_, Sep 23 2015 *)
%o A171386 (PARI) a(n)=n==2||n==3 \\ _Charles R Greathouse IV_, Sep 24 2015
%Y A171386 Cf. A000007, A010051, A063524.
%K A171386 nonn,easy,less
%O A171386 1,1
%A A171386 _Juri-Stepan Gerasimov_, Dec 07 2009
%E A171386 Edited by _Charles R Greathouse IV_, Mar 23 2010