Search: id:A160764 Results 1-1 of 1 results found. %I A160764 %S A160764 1,1,2,2,2,3,2,2,2,2,3,3,2,2,3,3,2,1,1,2,2,2,3, %T A160764 2,3,4,3,4,5,3,4,2,1,1,1,1,2,2,2,1,1,2,2,2,3,3, %U A160764 3,2,3,3,2,3,2,3,3,3,3,2,3,4,3,1,2,2,2,3,3,3,4 %V A160764 -1,-1,-2,-2,-2,-3,-2,-2,-2,-2,-3,-3,-2,-2,-3,-3,-2,-1,-1,-2,-2,-2,-3, %W A160764 -2,-3,-4,-3,-4,-5,-3,-4,-2,-1,-1,-1,-1,-2,-2,-2,-1,-1,-2,-2,-2,-3,-3, %X A160764 -3,-2,-3,-3,-2,-3,-2,-3,-3,-3,-3,-2,-3,-4,-3,-1,-2,-2,-2,-3,-3,-3,-4 %N A160764 a(n) = n-th square-free number minus round(n*zeta(2)). %C A160764 Race between the n-th square-free number and round(n*zeta(2)). %H A160764 Daniel Forgues, Table of n, a(n) for n=1..60794 %F A160764 Since zeta(2) = Sum[{i, 1, inf}, {1/(i^2)}] = (pi^2)/6, we get: %F A160764 a(n) = A005117(n) - n * Sum[{i, 1, inf}, {1/(i^2)}] = O(sqrt(n)) %F A160764 a(n) = A005117(n) - n * (pi^2)/6 = O(sqrt(n)) %Y A160764 Cf. A005117 Square-free numbers. %Y A160764 Cf. A013929 Not square-free numbers. %Y A160764 Cf. A013928 Number of square-free numbers < n. %Y A160764 Cf. A158819 Number of square-free numbers <= n minus round(n/zeta(2)). %Y A160764 Sequence in context: A089367 A130192 A104564 this_sequence A156384 A064656 A056608 %Y A160764 Adjacent sequences: A160761 A160762 A160763 this_sequence A160765 A160766 A160767 %K A160764 sign %O A160764 1,3 %A A160764 Daniel Forgues (squid(AT)zensearch.com), May 26 2009 Search completed in 0.001 seconds