Search: id:A068074 Results 1-1 of 1 results found. %I A068074 %S A068074 1,1,3,1,3,3,3,3,5,3,3,3,3,3,9,5,3,5,3,3,9,3,3,9,5,3,7,3,3,9,3,7,9,3,9, %T A068074 5,3,3,9,9,3,9,3,3,15,3,3,15,5,5,9,3,3,7,9,9,9,3,3,9,3,3,15,9,9,9,3,3, %U A068074 9,9,3,15,3,3,15,3,9,9,3,15,9,3,3,9,9,3,9,9,3,15,9,3,9,3,9 %V A068074 -1,-1,-3,1,-3,-3,-3,3,-5,-3,-3,3,-3,-3,-9,5,-3,-5,-3,3,-9,-3,-3,9,-5, -3,-7,3,-3,-9, %W A068074 -3,7,-9,-3,-9,5,-3,-3,-9,9,-3,-9,-3,3,-15,-3,-3,15,-5,-5,-9,3,-3,-7,-9, 9,-9,-3,-3,9, %X A068074 -3,-3,-15,9,-9,-9,-3,3,-9,-9,-3,15,-3,-3,-15,3,-9,-9,-3,15,-9,-3,-3,9, -9,-3,-9,9,-3 %N A068074 a(n)=sum(d|n,(-1)^d*2^omega(n/d)) where omega(x) is the number of distinct prime factors in x factorization. %D A068074 G. Tenenbaum and Jie Wu, Cours specialies No. 2: "Exercices corriges de theorie analytique et probabiliste des nombres", Collection SMF, chap. II.7.1, p. 105. %F A068074 Asymptotic formula : sum(k=1, n, a(k)/k)=-C*ln(n)^2 with C=3*ln(2)/Pi^2 %F A068074 a(n) = -tau(n^2) for odd n and 2*tau(n^2/4)-tau(n^2) for even n. b(n) = abs(a(n)) is multiplicative with b(2^e) = abs(2*e-3) and b(p^e) = 2*e+1 for an odd prime p. - Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 25 2002 %Y A068074 Cf. A048691. %Y A068074 Sequence in context: A059789 A023136 A152774 this_sequence A063195 A025796 A024163 %Y A068074 Adjacent sequences: A068071 A068072 A068073 this_sequence A068075 A068076 A068077 %K A068074 easy,nice,sign %O A068074 1,3 %A A068074 Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 14 2002 Search completed in 0.002 seconds