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 A333638 #17 Sep 08 2022 08:46:25 %S A333638 1,2,3,5,6,7,8,9,10,11,12,13,14,15,17,18,19,20,21,22,23,24,26,27,29, %T A333638 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,49,50,51,53,54, %U A333638 55,56,57,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74 %N A333638 Numbers m such that (m * sigma(m)) / tau(m) is an integer k. %C A333638 Corresponding values of integers k: 1, 3, 6, 15, 18, 28, 30, 39, 45, 66, 56, 91, 84, 90, 153, 117, 190, 140, 168, ... %C A333638 Supersequence of refactorable (A033950), arithmetic (A003601) and refactorable arithmetic numbers (A047727). %C A333638 Sequence of numbers from this sequence that are neither refactorable nor arithmetic: 10, 26, 32, 34, 50, 58, 63, 74, 75, 82, 90, 98, 106, 117, 120, 122, 130, 146, ... %e A333638 10 is a term because (10 * sigma(10)) / tau(10) = (10 * 18) / 4 = 45 (integer). %t A333638 Select[Range[100], Divisible[# * DivisorSigma[1, #], DivisorSigma[0, #]] &] (* _Amiram Eldar_, Mar 31 2020 *) %o A333638 (Magma) [m: m in [1..10^5] | IsIntegral((&+Divisors(m) * m) / #Divisors(m))] %o A333638 (PARI) isok(m) = (m*sigma(m) % numdiv(m)) == 0; \\ _Michel Marcus_, Mar 31 2020 %Y A333638 Cf. A000005, A000203, A033950, A047727. %K A333638 nonn %O A333638 1,2 %A A333638 _Jaroslav Krizek_, Mar 30 2020