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Search: id:A054785
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%I A054785
%S A054785 2,4,8,8,12,16,16,16,26,24,24,32,28,32,48,32,36,52,40,48,64,48,48,64,
%T A054785 62,56,80,64,60,96,64,64,96,72,96,104,76,80,112,96,84,128,88,96,156,96,
%U A054785 96,128,114,124,144,112,108,160,144,128,160,120,120,192,124,128,208
%N A054785 Sigma[2n]-Sigma[n], where Sigma is the sum of divisors of n, A000203.
%C A054785 n=9: sigma(2n)=18+9+6+3+2+1=39, sigma(n)=9+3+1=13, a(n)=39-13=26.
%F A054785 a(n)=A000203(2n)-A000203(n)
%F A054785 a(2*n) = A000203(n) + A000593(2*n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Apr 23 2008
%Y A054785 Cf. A000203.
%Y A054785 Equals 2 * A002131.
%Y A054785 Sequence in context: A129280 A103224 A078750 this_sequence A123263 A008218 
               A073043
%Y A054785 Adjacent sequences: A054782 A054783 A054784 this_sequence A054786 A054787 
               A054788
%K A054785 nonn
%O A054785 1,1
%A A054785 Labos E. (labos(AT)ana.sote.hu), May 22 2000

    
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Last modified December 5 23:38 EST 2009. Contains 170428 sequences.


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