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 A046987 #22 May 09 2024 02:57:00
%S A046987 120,523776,1476304896,31998395520,30823866178560,
%T A046987 69357059049509038080,4010059765937523916800,27099073228001299660800,
%U A046987 686498980761986918441287680,2827987212986831882236723200,115131961034430181728489308160,13361233986454282110797768294400,32789312424503984621373515366400
%N A046987 Multiply perfect numbers that are neither harmonic numbers nor arithmetic numbers.
%H A046987 Amiram Eldar, <a href="/A046987/b046987.txt">Table of n, a(n) for n = 1..100</a>
%F A046987 Let s1 be the sum of divisors of k and s0 be the number of divisors of k. Then, k is a term if k | s1, but (k * s0) is not divisible by s1, and s1 is not divisible by s0.
%e A046987 k = 523776 is a term since s0 = d(k) = 80, s1 = sigma(k) = 1571328, s1/k = 1571328/523776 = 3 is an integer, but (k * s0)/s1 = 80/3 and s1/s0 = 98208/5 are not integers.
%t A046987 q[n_] := Module[{d = DivisorSigma[0, n], s = DivisorSigma[1, n]}, Divisible[s, n] && !Divisible[n * d, s] && !Divisible[s, d]]; Select[Range[6*10^5], q] (* _Amiram Eldar_, May 09 2024 *)
%o A046987 (PARI) is(k) = {my(f = factor(k), s = sigma(f), d = numdiv(f)); !(s % k) && ((k * d) % s) && (s % d);} \\ _Amiram Eldar_, May 09 2024
%Y A046987 In A007691 but neither in A003601 nor in A001599.
%Y A046987 Cf. A000005, A000203, A046985, A046986.
%K A046987 nonn
%O A046987 1,1
%A A046987 _Labos Elemer_
%E A046987 a(5)-a(10) from _Donovan Johnson_, Nov 30 2008
%E A046987 Edited and a(11)-a(13) added by _Amiram Eldar_, May 09 2024