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.

A348605 Odd nonexponential abundant numbers: odd numbers k such that A160135(k) > k.

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%I A348605 #11 Oct 26 2021 04:27:34
%S A348605 8505,10395,12285,15015,16065,17955,19635,21735,21945,23205,25515,
%T A348605 25935,26565,28875,31185,31395,33495,33915,34125,35805,36855,39585,
%U A348605 41055,42315,42735,45885,47355,48195,49665,50505,51765,53865,54285,55965,56595,58695,61215,64155
%N A348605 Odd nonexponential abundant numbers: odd numbers k such that A160135(k) > k.
%C A348605 The odd terms of A348604.
%C A348605 The numbers of terms not exceeding 10^k, for k = 4, 5, ..., are 1, 51, 360, 4117, 39803, 418663, 4099004, ... Apparently this sequence has an asymptotic density 0.0004...
%H A348605 Amiram Eldar, <a href="/A348605/b348605.txt">Table of n, a(n) for n = 1..10000</a>
%e A348605 8505 is a term since A160135(8505) = 8862 > 8505.
%t A348605 esigma[n_] := Times @@ (Sum[First[#]^d, {d, Divisors[Last[#]]}] &) /@ FactorInteger[n]; q[n_] := DivisorSigma[1, n] - esigma[n] > n; Select[Range[1, 65000, 2], q]
%Y A348605 Cf. A160135.
%Y A348605 Subsequence of A005231 and A348604.
%Y A348605 Similar sequences: A094889, A127666, A129485, A293186, A321147, A348275.
%K A348605 nonn
%O A348605 1,1
%A A348605 _Amiram Eldar_, Oct 25 2021