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%I #11 Oct 15 2013 22:31:12
%S 0,5,74,831,8770,90407,921501,9335420,94238544,949152465,9544947488,
%T 95881945186,962392087981,9653934463160,96795058249197,
%U 970155429577330,9720761658966074,97376442842345766,975260045712259139,9765942332723655392,97779180397439081159
%N Number of composites <= 10^n.
%C Also, the order number of 10^n as a composite number.
%F a(n) = 10^n - 1 - A006880(n). - _Max Alekseyev_, Aug 15 2013
%F For n>0, a(n) = A092871(n) + 1.
%e 10 is the 5th composite number: 4,6,8,9,10.
%t Table[ 10^n- (PrimePi[10^n]) -1, {n, 1, 13} ]
%Y Cf. A002808.
%K nonn
%O 0,2
%A _Labos Elemer_, Nov 28 2001
%E More terms from _Robert G. Wilson v_, Nov 29 2001
%E Formula and more terms from _Max Alekseyev_, Aug 15 2013
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