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 A366641 #13 Apr 22 2025 05:21:24
%S A366641 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 A366641 46,47,51,53,57,58,59,61,62,66,67,69,71,73,74,77,78,82,83,86,87,89,91,
%U A366641 93,94,97,101,102,103,106,107,109,111,113,114,118,119,122,123,127
%N A366641 Squarefree numbers that are coprime to the terms of A366640.
%C A366641 First differs from A274546 at n = 42.
%C A366641 The asymptotic density of this sequence is 1/2.
%H A366641 Amiram Eldar, <a href="/A366641/b366641.txt">Table of n, a(n) for n = 1..10000</a>
%F A366641 a(n) ~ 2*n.
%F A366641 Sum_{n>=1} 1/a(n)^s = (zeta(s)/zeta(2*s)) / Product_{p in A366640} (1 + 1/p^s), s>1.
%t A366641 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 A366641 Subsequence of A005117 and A274546.
%Y A366641 Cf. A056911, A261034, A366640.
%K A366641 nonn,easy
%O A366641 1,2
%A A366641 _Amiram Eldar_, Oct 15 2023