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 A336561 #8 Jul 26 2020 09:51:21
%S A336561 506,1819,2024,2714,3674,3818,4554,5088,5750,5786,6026,6762,6842,7215,
%T A336561 7276,9487,9523,10442,11895,12397,12650,13178,13303,14235,14696,15272,
%U A336561 15962,16346,16371,18216,18458,19274,19514,19690,19706,20179,20378,21079,21255,21626,22066,22586,22682,23000,23144,23322,24104,24246
%N A336561 Numbers k at which point A336459(k) appears multiplicative, but A051027(k) does not.
%H A336561 Antti Karttunen, <a href="/A336561/b336561.txt">Table of n, a(n) for n = 1..11481</a>
%H A336561 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%e A336561 506 = 2*11*23 is a term as A336459(2)*A336459(11)*A336459(23) = 1*7*5 = 35 = A336459(506), while A051027(2)*A051027(11)*A051027(23) = 4*28*60 = 6720 <> A051027(506) = 2520. Note that 2520 = 2^3 * 3^2 * 5 * 7, thus A065330(2520) = 5*7 = 35.
%o A336561 (PARI)
%o A336561 is_fun_mult_on_n(fun,n) = { my(f=factor(n)); prod(k=1,#f~,fun(f[k,1]^f[k,2]))==fun(n); };
%o A336561 A051027(n) = sigma(sigma(n));
%o A336561 A336546(n) = is_fun_mult_on_n(A051027,n);
%o A336561 A065330(n) = (n>>valuation(n, 2)/3^valuation(n, 3));
%o A336561 A336459(n) = A065330(A051027(n));
%o A336561 isA336561(n) = (A336546(n)<is_fun_mult_on_n(A336459,n));
%Y A336561 Cf. A051027, A065330, A336459.
%Y A336561 Cf. also A336549.
%Y A336561 Subsequence of A336548, and probably also of A336560.
%K A336561 nonn
%O A336561 1,1
%A A336561 _Antti Karttunen_, Jul 25 2020