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 A290496 #9 Aug 18 2017 20:11:35
%S A290496 1,1,1,1,1,3,1,2,1,3,2,3,1,3,3,2,3,3,1,3,2,3,1,6,5,1,2,1,5,4,2,1,5,3,
%T A290496 1,3,3,5,3,4,2,3,1,2,4,5,4,5,4,3,3,2,3,4,3,2,6,1,5,3,1,6,5,1,2,10,2,1,
%U A290496 3,2,3,4,5,3,4,5,3,1,2,4,6,2,10,3,3,5,1
%N A290496 First differences of A001751.
%t A290496 With[{nn = 56}, Differences@ Union@ Flatten@ {#, 2 TakeWhile[#, # < Prime[nn]/2 &]} &@ Prime@ Range@ nn]
%o A290496 (PARI) lista(nn) = {last = 2; for (n=3, nn, if (isprime(n) || (!(n%2) && isprime(n/2)), print1(n - last, ", "); last = n;););}
%Y A290496 Cf. A001751, A290488, A290489, A290541.
%K A290496 nonn
%O A290496 1,6
%A A290496 _Michel Marcus_, Aug 04 2017