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A095300 Numbers n such that A094758(n) < n. 3

%I #16 Jan 18 2024 03:08:08

%S 2,6,10,12,14,18,22,24,26,30,34,38,42,46,50,54,58,60,62,66,70,74,78,

%T 82,84,86,90,94,96,98,102,106,110,114,118,120,122,126,130,132,134,138,

%U 142,146,150,154,156,158,162,166,168,170,174,178,182,186,190,194,198,202

%N Numbers n such that A094758(n) < n.

%C The numbers of terms not exceeding 10^k, for k = 1, 2, ..., are 3, 30, 298, 2990, 29881, 298792, 2987904, 29879025, ... . Apparently, the asymptotic density of this sequence exists and equals 0.29879... . - _Amiram Eldar_, Jan 18 2024

%H Amiram Eldar, <a href="/A095300/b095300.txt">Table of n, a(n) for n = 1..10000</a>

%e A094758(2) = 1 < 2, hence 2 is in the sequence.

%t aQ[n_] := Module[{k = 1, r = DivisorSigma[0, n]/n}, While[DivisorSigma[0, k]/k != r, k++]; k < n]; Select[Range[200], aQ] (* _Amiram Eldar_, Aug 19 2019 *)

%o (PARI) for(n=1,205,s=numdiv(n);k=1;while(n*numdiv(k)!=k*s,k++);if(k<n,print1(n,",")));

%Y Cf. A000005, A094758.

%K nonn

%O 1,1

%A _Klaus Brockhaus_, Jun 01 2004

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Last modified April 23 02:53 EDT 2024. Contains 371906 sequences. (Running on oeis4.)