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.

A348627 Numbers that are both exponential and nonexponential abundant numbers.

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%I A348627 #8 Oct 26 2021 16:52:44
%S A348627 3600,4500,6300,7056,8100,8820,9900,14700,21780,22500,25200,30420,
%T A348627 31500,35280,39600,46800,49500,52020,56700,58500,61200,61740,64980,
%U A348627 68400,69300,76500,77616,81900,82800,85500,88200,89100,91728,95220,97020,103500,104400,105300
%N A348627 Numbers that are both exponential and nonexponential abundant numbers.
%H A348627 Amiram Eldar, <a href="/A348627/b348627.txt">Table of n, a(n) for n = 1..10000</a>
%e A348627 3600 is a term since A051377(3600) = 7920 > 2*3600 and A160135(3600) = 4573 > 3600.
%t A348627 esigma[n_] := Times @@ (Sum[First[#]^d, {d, Divisors[Last[#]]}] &) /@ FactorInteger[n]; Select[Range[10^5], (e = esigma[#]) > 2*# && DivisorSigma[1, #] - e > # &]
%Y A348627 Cf. A051377, A160135.
%Y A348627 Intersection of A129575 and A348604.
%Y A348627 Subsequence of A068403.
%Y A348627 Similar sequence: A348523.
%K A348627 nonn
%O A348627 1,1
%A A348627 _Amiram Eldar_, Oct 26 2021