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 A377952 #7 Nov 13 2024 17:23:00
%S A377952 1,30,60,90,105,132,180,210,252,264,360,380,420,495,504,520,528,546,
%T A377952 630,660,756,840,858,870,924,990,1040,1056,1092,1140,1224,1260,1320,
%U A377952 1365,1485,1512,1530,1560,1638,1656,1716,1722,1740,1785,1820,1848,1900,1980,2040
%N A377952 Numbers k that divide A084190(k) = lcm{d-1 : d > 1 and d|k}.
%C A377952 After the first term a(1) = 1, the next odd term is a(5) = 105, the next term that is coprime to 6 is a(133) = 6545, and the next term that is coprime to 30 is a(322) = 19019.
%H A377952 Amiram Eldar, <a href="/A377952/b377952.txt">Table of n, a(n) for n = 1..10000</a>
%t A377952 Select[Range[2000], # == 1 || Divisible[LCM @@ (Rest @ Divisors[#] - 1), #] &]
%o A377952 (PARI) is(k) = !(lcm(apply(x -> if(x > 1, x-1, x), divisors(k))) % k);
%Y A377952 Cf. A084190.
%Y A377952 A377953 is a subsequence.
%Y A377952 Similar sequences: A056954, A355331, A377950.
%K A377952 nonn,easy
%O A377952 1,2
%A A377952 _Amiram Eldar_, Nov 12 2024