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 A033559 #11 Mar 16 2014 03:06:51
%S A033559 1,2,1,3,2,2,2,3,1,3,2,2,2,3,1,3,2,2,2,5,3,3,3,3,3,4,1,4,3,3,3,3,3,5,
%T A033559 2,2,2,3,1,3,2,2,2,5,3,3,3,3,3,6,3,3,3,3,3,4,1,4,3,3,3,3,3,5,2,2,2,3,
%U A033559 1,4,3,3,3,3,3,5,2,2,2,5,3,3,3,3,3,7,4,4,4,4,4,4,4,6,2,2,2
%N A033559 a(n) = (q - p)/2, where p is the largest prime < n and q is the smallest prime > n.
%H A033559 Jean-François Alcover, <a href="/A033559/a033559.txt">Frequency distribution up to 10^6 terms.</a>
%t A033559 a[n_] := (NextPrime[n] - NextPrime[n, -1])/2; Table[a[n], {n, 4, 100}] (* _Jean-François Alcover_, Apr 16 2013 *)
%K A033559 nonn
%O A033559 4,2
%A A033559 _N. J. A. Sloane_
%E A033559 More terms from _Ben Paul Thurston_, Mar 30 2007