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Search: id:A066264
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| A066264 |
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Number of composites < primorial(p) with all prime factors > p. |
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+0
1
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| 0, 0, 0, 5, 141, 2517, 49835, 1012858, 24211837, 721500293, 22627459400, 844130935667, 34729870646917
(list; graph; listen)
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OFFSET
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0,4
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COMMENT
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There is a simple relationship between this sequence and the number of primes < primorial(p), as given by A000849 and sequence A005867 which gives the number of composites in primorial(p+1) having (p+1) as their lowest prime factor: a(n) = n + A005867(n+1) - A000849(n) - 1. - Dennis Martin (dennis.martin(AT)dptechnology.com), Apr 15 2007
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LINKS
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Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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EXAMPLE
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There are 5 composites < primorial(7) or 210 and whose prime factors are all larger than 7: 121 (11*11), 143 (11*13), 169 (13*13), 187 (11*17) and 209 (11*19).
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CROSSREFS
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Cf. A002110.
Cf. A000849, A005867.
Adjacent sequences: A066261 A066262 A066263 this_sequence A066265 A066266 A066267
Sequence in context: A061320 A136464 A006269 this_sequence A037049 A134503 A081322
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KEYWORD
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nonn
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AUTHOR
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Patrick De Geest (pdg(AT)worldofnumbers.com), Dec 10 2001.
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EXTENSIONS
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More terms from Dennis Martin (dennis.martin(AT)dptechnology.com), Apr 15 2007
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