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Search: id:A075868
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%I A075868
%S A075868 3,6,15,20,21,28,35,50,66,98,99,104,105,114,125,130,154,170,210,230,
%T A075868 276,325,351,352,363,372,374,380,414,444,459,476,532,539,558,572,580,
%U A075868 585,608,666,693,696,845,847,950,968,975
%N A075868 tau(n) = phi(sum of prime factors of n).
%e A075868 tau(50) = number of divisors of 50 = 6; phi(sum of prime factors of 50) 
               = phi(2 + 5) = 6. Hence 50 is a term of the sequence.
%t A075868 Select[Range[2, 10^3], EulerPhi[Apply[Plus, Transpose[FactorInteger[ 
               # ]][[1]]]] == DivisorSigma[0, # ] &]
%Y A075868 Sequence in context: A124518 A160724 A060304 this_sequence A162335 A095869 
               A069559
%Y A075868 Adjacent sequences: A075865 A075866 A075867 this_sequence A075869 A075870 
               A075871
%K A075868 nonn
%O A075868 2,1
%A A075868 Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Oct 15 2002

    
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Last modified December 10 12:37 EST 2009. Contains 170569 sequences.


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