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 A091428 #11 Jan 11 2023 06:39:37 %S A091428 1,3,4,5,7,11,12,13,15,17,19,20,21,23,28,29,31,33,35,37,39,41,43,44, %T A091428 47,51,52,53,55,57,59,60,61,65,67,68,69,71,73,76,77,79,83,84,85,87,89, %U A091428 91,92,93,95,97,101,103,105,107,109,111,113,115,116,119,123,124,127,129 %N A091428 Numbers k such that abs(A092673(k)) = 1. %C A091428 The asymptotic density of this sequence is 5/Pi^2 = 0.506605... . - _Amiram Eldar_, Jan 11 2023 %H A091428 Amiram Eldar, <a href="/A091428/b091428.txt">Table of n, a(n) for n = 1..10000</a> %t A091428 Select[Range[130], Abs[MoebiusMu[#] - If[EvenQ[#], MoebiusMu[#/2], 0]] == 1 &] (* _Amiram Eldar_, Jan 11 2023 *) %Y A091428 Disjoint union of A056911 and A081770. %Y A091428 Cf. A092673, A359592 (characteristic function). %Y A091428 Distinct from A020486. %K A091428 nonn %O A091428 1,2 %A A091428 _Jon Perry_, Mar 02 2004