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A083682 Sum of aliquot divisors of semiprimes. 1

%I

%S 3,6,4,8,10,9,11,14,6,16,15,20,13,22,17,26,8,21,17,23,32,34,19,27,40,

%T 19,44,23,46,33,21,35,50,25,56,41,29,62,25,12,64,45,47,27,70,51,74,25,

%U 35,76,37,82,57,31,86,14,63,92,65,43,29,100,71,104,37,47,106,31,75,110,49

%N Sum of aliquot divisors of semiprimes.

%H Amiram Eldar, <a href="/A083682/b083682.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A001065(A001358(n)). - _Amiram Eldar_, Sep 23 2019

%e a(1)=3 because sum of aliquot divisors of first semiprime i.e. 4 is 1+2=3.

%t s[n_] := DivisorSigma[1, n] - n; s /@ Select[Range[300], PrimeOmega[#]==2 &] (* _Amiram Eldar_, Sep 23 2019 *)

%Y Cf. A001065, A001358.

%K easy,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Jun 15 2003

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Last modified September 23 04:54 EDT 2020. Contains 337295 sequences. (Running on oeis4.)