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%I #17 Mar 15 2018 04:35:58
%S 0,0,0,0,1,0,1,0,1,1,2,0,2,1,1,1,3,1,3,1,2,2,3,0,3,3,3,2,4,1,4,2,3,3,
%T 3,1,5,4,4,2,5,2,5,3,3,4,5,1,5,4,5,4,6,3,5,3,5,5,6,1,6,5,4,4,6,4,7,5,
%U 6,4,7,2,7,6,5,5,6,4,7,3,6,7,8,3,7,7,7,5,8,3,7,6,7,7,7,3,8,6,6,5,9
%N Number of positive integers <= sqrt(n) not dividing n.
%C It appears that the indices of the zeros in the sequence are in A018253.
%H Omar E. Pol, , <a href="http://www.polprimos.com/imagenespub/poldiv13.jpg">Three illustrations of A000005 giving the structure of this sequence</a>, (2013)
%F a(n) = A000196(n) - A038548(n) = A160812(n)/2.
%o (PARI) a(n) = sum(i=1, sqrtint(n), (n % i) != 0); \\ _Michel Marcus_, Mar 16 2014
%Y Cf. A000005, A000196, A010052, A018253, A038548, A007491, A160812, A161205, A212119, A228813, A228814, A229940, A229942, A229944, A229950, A229951.
%K nonn
%O 1,11
%A _Omar E. Pol_, Feb 05 2014