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%I #3 Mar 30 2012 18:50:31
%S 1,2,3,4,5,6,7,8,9,9,10,11,12,12,13,14,15,16,17,17,17,17,18,19,20,20,
%T 21,21,22,22,23,24,24,24,25,26,27,27,27,27,28,28,29,29,30,30,31,32,33,
%U 33,33,33,34,35,35,35,35,35,36,36,37,37,37,38,38,38,39,39,39,39,40,41,42
%N Number of numbers m <= n with prime factors less than 2*spf(m), where spf(m) is the smallest prime factor of m (A020639).
%C a(n)+A081305(n)=n; a(114)=A081305(114)=57;
%C a(n)>=n/2 for n<=114, a(n)<n/2 for n>114.
%Y Cf. A081306, A081303.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Mar 17 2003