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Search: id:A141501
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| A141501 |
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a(n) is smallest integer for which the number of integers from 1 to a(n) that are not divisors of n is greater than the number of integers from 1 to a(n) that are divisors of n. |
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+0
2
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| 3, 5, 5, 7, 3, 9, 3, 7, 5, 7, 3, 11, 3, 5, 7, 7, 3, 11, 3, 9, 5, 5, 3, 15, 3, 5, 5, 9, 3, 13, 3, 7, 5, 5, 3, 15, 3, 5, 5, 13, 3, 11, 3, 7, 7, 5, 3, 15, 3, 7, 5, 7, 3, 11, 3, 11, 5, 5, 3, 19, 3, 5, 5, 7, 3, 9, 3, 7, 5, 9, 3, 17, 3, 5, 7, 7, 3, 9, 3, 13, 5, 5, 3, 17, 3, 5, 5, 7, 3, 17, 3, 7, 5, 5, 3, 15, 3, 5
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Is a(n) always odd??
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EXAMPLE
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a(6) = 9 because among the integers 1 through 9 we have:
Divisors: 1, 2, 3, 6
Non-divisors: 4, 5, 7, 8, 9
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PROGRAM
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(PARI) {for(n=1, 100, k=1; d=divisors(n); while(1, c=0; for(j=1, #d, if(d[j]<=k, c++)); if(k-c<=c, k++, break)); print1(k, ", "))} [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 18 2008]
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CROSSREFS
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Cf. A143474 (smallest k such that A141501(k) = 2*n+1). [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 25 2008]
Sequence in context: A029912 A010616 A055594 this_sequence A103988 A086269 A057952
Adjacent sequences: A141498 A141499 A141500 this_sequence A141502 A141503 A141504
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KEYWORD
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nonn
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AUTHOR
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J. Lowell (jhbubby(AT)mindspring.com), Aug 10 2008
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EXTENSIONS
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Extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 18 2008
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