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%I A045763
%S A045763 0,0,0,0,0,1,0,1,1,3,0,3,0,5,4,4,0,7,0,7,6,9,0,9,3,11,6,11,0,15,0,11,10,
%T A045763 15,8,16,0,17,12,17,0,23,0,19,16,21,0,23,5,25,16,23,0,29,12,25,18,27,0,
%U A045763 33,0,29,22,26,14,39,0,31,22,39,0,37,0,35,30,35,14,47,0,39,23,39,0,49
%N A045763 Number of numbers "unrelated to n": m<n such that m is neither a divisor 
               of n nor relatively prime to n.
%C A045763 a(n)=0 iff n is a prime or 1 or 4. - Robert G. Wilson v (rgwv(at)rgwv.com), 
               Nov 02 2005
%D A045763 Martin Beumer, The Arithmetical Function tau_k(N), Amer. Math. Monthly, 
               69, Oct 1962, p. 780 (a(n)=ksi(N)).
%D A045763 Suggested by Wouter Meeussen (wouter.meeussen(AT)pandora.be)
%H A045763 T. D. Noe, <a href="b045763.txt">Table of n, a(n) for n=1..1000</a>
%F A045763 n + 1 - d(n) - phi(n); where d is the number of divisors of n and phi 
               is Euler's totient function.
%t A045763 f[n_] := n + 1 - DivisorSigma[0, n] - EulerPhi[n]; Array[f, 84] (* Robert 
               G. Wilson v *)
%Y A045763 Sequence in context: A053387 A141030 A100258 this_sequence A132748 A055945 
               A138123
%Y A045763 Adjacent sequences: A045760 A045761 A045762 this_sequence A045764 A045765 
               A045766
%K A045763 nonn
%O A045763 1,10
%A A045763 N. J. A. Sloane (njas(AT)research.att.com).
%E A045763 More terms from Robert G. Wilson v (rgwv(at)rgwv.com), Nov 02 2005

    
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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


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