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Search: id:A138109
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| A138109 |
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Positive integers n whose smallest prime factor is greater than the cube root of n and strictly less than the square root of n. |
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+0
1
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| 6, 15, 21, 35, 55, 65, 77, 85, 91, 95, 115, 119, 133, 143, 161, 187, 203, 209, 217, 221, 247, 253, 259, 287, 299, 301, 319, 323, 329, 341, 377, 391, 403, 407, 437, 451, 473, 481, 493, 517, 527, 533, 551, 559, 583, 589, 611, 629, 649, 667, 671, 689, 697, 703
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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This sequence was suggested by Moshe Newman
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EXAMPLE
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a(1)=6 because the smallest prime factor of 6 is 2 and 1.817...<2<2.449...
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MATHEMATICA
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s = {}; Do[f = FactorInteger[i]; test = f[[1]][[1]]; If [test < N[i^(1/2)] && test > N[i^(1/3)], s = Union[s, {i}]], {i, 2, 2000}]; Print[s]
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CROSSREFS
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Sequence in context: A009092 A015793 A063466 this_sequence A072521 A130178 A100410
Adjacent sequences: A138106 A138107 A138108 this_sequence A138110 A138111 A138112
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KEYWORD
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nonn
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AUTHOR
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David S. Newman (davidsnewman(AT)gmail.com), May 04 2008
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