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A108276
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Number of positive integers <= 10^n that are divisible by no prime exceeding 19.
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1
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1, 10, 72, 331, 1169, 3419, 8751, 20198, 42950, 85411, 160626, 288126, 496303, 825326, 1330766, 2088013, 3197529, 4791093, 7039193, 10159603, 14427309, 20186026, 27861175, 37974797, 51162295, 68191379, 89983125, 117635672
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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MATHEMATICA
| n = 9; t = Select[ Flatten[ Table[19^h*Select[ Flatten[ Table[17^g*Select[ Flatten[ Table[13^f*Select[ Flatten[ Table[11^e*Select[ Flatten[ Table[7^d*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 &], {d, 0, n*Log[7, 10]}]], # <= 10^n &], {e, 0, n*Log[11, 10]}]], # <= 10^n &], {f, 0, n*Log[13, 10]}]], # <= 10^n &], {g, 0, n*Log[17, 10]}]], # <= 10^n &], {h, 0, n*Log[19, 10]}]], # <= 10^n &]; Table[ Length[ Select[t, # <= 10^n &]], {n, 0, 10}]
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CROSSREFS
| Cf. A123384, A100752, A106598, A106600, A107352, A106629, A108275, A108277 [From Max Alekseyev (maxale(AT)gmail.com), Apr 28 2010]
Sequence in context: A049672 A037579 A166791 * A164546 A037712 A037614
Adjacent sequences: A108273 A108274 A108275 * A108277 A108278 A108279
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KEYWORD
| nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), May 31 2005
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EXTENSIONS
| a(10)-a(18) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Sep 16 2009
a(19)-a(27) from Max Alekseyev (maxale(AT)gmail.com), Apr 28 2010
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