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 A376142 #9 Mar 07 2025 10:58:04
%S A376142 8,24,27,32,40,54,56,72,88,96,104,108,120,125,128,135,136,152,160,168,
%T A376142 184,189,200,216,224,232,243,248,250,264,270,280,288,296,297,312,328,
%U A376142 343,344,351,352,360,375,376,378,384,392,408,416,424,440,456,459,472,480,486,488,500
%N A376142 Nonsquarefree numbers whose prime factorization has a maximum exponent that is odd.
%C A376142 Subsequence of A060476 and differs from it by not having the terms 1, 256, 768, 1280, 1792, 2304, ... .
%C A376142 Subsequence of A295661 and first differs from it at n = 51: A295661(51) = 432 is not a term of this sequence.
%C A376142 First differs from A325990 at n = 30: A325990(30) = 256 is not a term of this sequence.
%C A376142 Nonsquarefree numbers k such that A051903(k) is odd, or equivalently, numbers k such that A051903(k) is an odd number that is larger than 1.
%C A376142 The asymptotic density of this sequence is Sum_{k>=3} (-1)^(k+1) * (1 - 1/zeta(k)) = 0.11615617754774636364... .
%H A376142 Amiram Eldar, <a href="/A376142/b376142.txt">Table of n, a(n) for n = 1..10000</a>
%t A376142 q[n_] := n > 1 && OddQ[n]; Select[Range[500], q[Max[FactorInteger[#][[;; , 2]]]] &]
%o A376142 (PARI) is(k) = k > 1 && apply(x -> (x > 1 && x % 2), vecmax(factor(k)[, 2]));
%Y A376142 Complement of A368714 within A013929.
%Y A376142 Cf. A051903, A060476, A295661, A325990.
%K A376142 nonn,easy
%O A376142 1,1
%A A376142 _Amiram Eldar_, Sep 11 2024