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 A106598 Number of positive integers <= 10^n that are divisible by no prime exceeding 5. 4

%I

%S 1,9,34,86,175,313,507,768,1105,1530,2053,2683,3429,4301,5310,6466,

%T 7780,9259,10917,12761,14801,17048,19511,22201,25127,28300,31730,

%U 35425,39397,43654,48207,53066,58243,63746,69584,75769,82310,89216,96499,104168

%N Number of positive integers <= 10^n that are divisible by no prime exceeding 5.

%t n = 40; t = Select[ Flatten[ Table[ 5^c*Select[ Flatten[ Table[2^a*3^b, {a, 0, n*Log[2, 10]}, {b, 0, n*Log[3, 10]}]], # <= 10^n &], {c, 0, n*Log[5, 10]}]], # <= 10^n &]; Table[ Length[ Select[t, # <= 10^n &]], {n, 0, 40}]

%K nonn

%O 0,2

%A _Robert G. Wilson v_, May 27 2005

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Last modified March 18 17:51 EDT 2019. Contains 321292 sequences. (Running on oeis4.)