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Search: id:A120632
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| A120632 |
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Number of numbers >1 up to 2*p(n) which are divisible by primes up to p(n). |
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4
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| 2, 4, 8, 11, 18, 22, 29, 33, 40, 51, 54, 64, 72, 76, 84, 94, 104, 109, 120, 127, 132, 142, 150, 161, 174, 181, 186, 194, 199, 207, 230, 238, 248, 252, 270, 275, 285, 297, 305, 317, 327, 331, 349, 353, 361, 365, 386, 407, 415, 419, 426, 438, 442, 460, 471, 482
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OFFSET
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1,1
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COMMENT
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The first p(n+1)-2 numbers >1 are divisible by primes up to p(n).
Complement of A137624; A137621(a(n))=A000040(n); A137621(a(n)+1)=A100484(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jan 30 2008
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FORMULA
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a(n) = A120633(n) + A040976(n+1) = A076274(n) - A070046(n).
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EXAMPLE
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a(4)=11 because exactly 11 numbers between 2 and 2*p(4)=2*7=14,namely,2,3,4,5,6,7,8,9,10,12,14 are divisible by the first four primes 2,3,5,7.
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CROSSREFS
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Adjacent sequences: A120629 A120630 A120631 this_sequence A120633 A120634 A120635
Sequence in context: A018320 A153195 A010068 this_sequence A007295 A053439 A033956
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KEYWORD
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nonn
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AUTHOR
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Lekraj Beedassy (blekraj(AT)yahoo.com), Jun 21 2006
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