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A079631
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Number of k less than or equal to n such that floor(k^(1/3)) divides k.
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4
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1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 30, 31, 31, 31, 31, 32, 32, 32, 32, 33, 33
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OFFSET
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1,2
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COMMENTS
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Concrete Mathematics Casino Problem - number of winners up to N.
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REFERENCES
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R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. 2nd Edition. Addison-Wesley, Reading, MA, 1994. Section 3.2, p74-76.
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LINKS
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FORMULA
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a(n)=floor(n/floor(n^(1/3)))+1/2*floor(n^(1/3))^2+5/2*floor(n^(1/3))-3
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EXAMPLE
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a(1000)=172
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MATHEMATICA
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Accumulate[Boole[Table[IntegerQ[n/Floor[n^(1/3)]], {n, 1, 73}]]] (* Geoffrey Critzer, May 25 2013 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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