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%I #10 Oct 16 2023 09:30:22
%S 1,2,3,6,7,11,13,14,17,19,21,22,23,26,29,31,33,34,37,38,39,41,42,43,
%T 46,47,51,53,57,58,59,61,62,66,67,69,71,73,74,77,78,82,83,86,87,89,91,
%U 93,94,97,101,102,103,106,107,109,111,113,114,118,119,122,123,127
%N Squarefree numbers that are coprime to the terms of A366640.
%C First differs from A274546 at n = 42.
%C The asymptotic density of this sequence is 1/2.
%H Amiram Eldar, <a href="/A366641/b366641.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) ~ 2*n.
%F Sum_{n>=1} 1/a(n)^s = (zeta(s)/zeta(2*s)) / Product_{p in A366640} (1 + 1/p^s), s>1.
%t seq[max_] := With[{ps = {5, 79, 1831}}, If[max <= Max[ps], Select[Range[max], And @@ CoprimeQ[#, ps] && SquareFreeQ[#] &], Print["Add to ps more terms from A366640"]]]; seq[130]
%Y Subsequence of A005117 and A274546.
%Y Cf. A056911, A261034, A366640.
%K nonn,easy
%O 1,2
%A _Amiram Eldar_, Oct 15 2023
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