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 A338357 #11 Feb 12 2024 07:28:52
%S A338357 1,2,-1,3,-1,5,-3,7,-6,1,2,11,-10,1,13,-11,1,1,17,-16,1,19,-18,1,2,23,
%T A338357 -22,1,2,1,1,29,-28,1,31,-30,1,2,1,1,37,-35,1,1,41,-40,1,43,-42,1,2,
%U A338357 47,-46,1,1,1,1,1,53,-52,1,1,1,2,59,-58,1,61,-59,1,1,1,1,67,-66,1,1,1,71
%N A338357 First differences of A283312.
%H A338357 N. J. A. Sloane, <a href="/A338357/b338357.txt">Table of n, a(n) for n = 1..10000</a>
%t A338357 Module[{nmax = 100, smn = 1}, Differences[Nest[Append[#, If[PrimeQ[Last[#]], 2*Last[#], While[MemberQ[#, ++smn]]; smn]]&, {1}, nmax]]] (* _Paolo Xausa_, Feb 12 2024 *)
%Y A338357 Cf. A283312.
%K A338357 sign
%O A338357 1,2
%A A338357 _N. J. A. Sloane_, Nov 03 2020