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%I #16 Sep 25 2023 18:55:54
%S 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 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 0,0,1,1,0,0,1,0,1,1,0,1,1,1,0,0,1,1,1
%N Gilbreath transform of semiprimes (A001358).
%H Paolo Xausa, <a href="/A365939/b365939.txt">Table of n, a(n) for n = 1..10000</a>
%H <a href="/index/Ge#Gilbreath">Index entries for sequences related to Gilbreath conjecture and transform</a>
%t 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 Leading terms of rows of the array in A131749.
%Y Cf. A001358, A196251, A361897, A362451.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Sep 25 2023.
%E More terms from _Pontus von Brömssen_, Sep 25 2023
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