cp's OEIS Frontend

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.

A348032 Multiply-perfect numbers k that do not have a divisor d such that sigma(d)*d = k.

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%I A348032 #12 Sep 28 2021 19:54:59
%S A348032 2178540,45532800,459818240,1476304896,14182439040,31998395520,
%T A348032 43861478400,51001180160,518666803200,704575228896,13661860101120,
%U A348032 30823866178560,181742883469056,740344994887680,796928461056000,6088728021160320,20158185857531904,212517062615531520,622286506811515392,69357059049509038080,87934476737668055040
%N A348032 Multiply-perfect numbers k that do not have a divisor d such that sigma(d)*d = k.
%C A348032 Numbers k in A007691 for which A327153(k) = 0, that are not in A327165.
%C A348032 Question: Is A323653 a subsequence of this sequence? See also conjecture in A348033.
%H A348032 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%t A348032 With[{s = DeleteCases[Map[ToExpression[#] &, Import["https://oeis.org/A007691/b007691.txt", "Data"]], _?(Length[#] == 0 &)][[All, -1]]}, Select[s[[1 ;; 45]], Function[k, NoneTrue[Divisors[k], # DivisorSigma[1, #] == k &]]]] (* _Michael De Vlieger_, Sep 28 2021, using b-file at A007691 *)
%Y A348032 Cf. A348031 (complement in A007691).
%Y A348032 Cf. A327153, A327165, A348033.
%K A348032 nonn
%O A348032 1,1
%A A348032 _Antti Karttunen_, Sep 26 2021