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 A365939 #18 Jul 09 2025 05:02:44
%S A365939 4,2,1,1,0,1,0,1,1,1,1,1,0,1,0,1,1,0,1,1,1,1,1,1,0,0,1,1,1,1,0,0,0,1,
%T A365939 1,1,1,1,0,0,1,1,0,0,1,1,1,1,0,0,1,1,0,0,0,1,0,0,0,1,0,0,0,0,1,0,0,0,
%U A365939 0,0,1,1,0,0,1,0,1,1,0,1,1,1,0,0,1,1,1
%N A365939 Gilbreath transform of semiprimes (A001358).
%H A365939 Paolo Xausa, <a href="/A365939/b365939.txt">Table of n, a(n) for n = 1..10000</a>
%H A365939 <a href="/index/Ge#Gilbreath">Index entries for sequences related to Gilbreath conjecture and transform</a>
%t A365939 A365939list[upto_]:=If[upto<4,{},Module[{d=Select[Range[upto],PrimeOmega[#]==2&]},Join[{4},Table[First[d=Abs[Differences[d]]],Length[d]-1]]]];A365939list[500] (* _Paolo Xausa_, Sep 25 2023 *)
%Y A365939 Leading terms of rows of the array in A131749.
%Y A365939 Cf. A001358, A196251, A361897, A362451.
%K A365939 nonn
%O A365939 1,1
%A A365939 _N. J. A. Sloane_, Sep 25 2023
%E A365939 More terms from _Pontus von Brömssen_, Sep 25 2023