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.

A348604 Nonexponential abundant numbers: numbers k such that A160135(k) > k.

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%I A348604 #11 Oct 26 2021 04:27:39
%S A348604 24,30,42,48,54,60,66,70,72,78,84,90,96,102,114,120,126,132,138,150,
%T A348604 156,160,162,168,174,180,186,192,198,210,216,222,224,240,246,258,264,
%U A348604 270,280,282,288,294,300,312,318,320,330,336,352,354,360,366,378,384,390
%N A348604 Nonexponential abundant numbers: numbers k such that A160135(k) > k.
%C A348604 The smallest odd term is a(1357) = 8505.
%C A348604 The numbers of terms not exceeding 10^k, for k = 1, 2, ..., are 0, 13, 148, 1595, 15688, 158068, 1578957, 15762209, 157745113, 1577808429, ... Apparently this sequence has an asymptotic density 0.157...
%H A348604 Amiram Eldar, <a href="/A348604/b348604.txt">Table of n, a(n) for n = 1..10000</a>
%e A348604 24 is a term since A160135(24) = 30 > 24.
%t A348604 esigma[n_] := Times @@ (Sum[First[#]^d, {d, Divisors[Last[#]]}] &) /@ FactorInteger[n]; q[n_] := DivisorSigma[1, n] - esigma[n] > n; Select[Range[400], q]
%Y A348604 Cf. A160135, A348601.
%Y A348604 Subsequence of A005101.
%Y A348604 Similar sequences: A034683, A064597, A129575, A129656, A292982, A348274.
%K A348604 nonn
%O A348604 1,1
%A A348604 _Amiram Eldar_, Oct 25 2021