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Search: id:A111905
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| A111905 |
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A number n is included if more primes, among primes <= the largest prime dividing n, divide n than do not. |
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+0
3
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| 2, 4, 6, 8, 10, 12, 15, 16, 18, 20, 24, 30, 32, 36, 40, 42, 45, 48, 50, 54, 60, 64, 66, 70, 72, 75, 80, 84, 90, 96, 100, 105, 108, 110, 120, 126, 128, 132, 135, 140, 144, 150, 154, 160, 162, 165, 168, 180, 192, 198, 200, 210, 216, 220, 225, 231, 240, 250, 252, 256, 264
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Leroy Quet, Home Page (listed in lieu of email address)
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EXAMPLE
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20 is included because 5 is the largest prime dividing 20. And of the primes <= 5 (2,3,5), 2 and 5 (2 primes) divide 20, 3 (only 1 prime) does not divide 20.
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PROGRAM
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(PARI) {m=270; v=vector(m); for(n=1, m, f=factor(n)[, 1]~; c=0; pc=0; forprime(p=2, vecmax(f), j=1; s=length(f); while(j<=s&&p!=f[j], j++); if(j<=s, c++); pc++); v[n]=sign(pc-2*c)); for(n=1, m, if(v[n]<0, print1(n, ", ")))} (Klaus Brockhaus)
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CROSSREFS
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Cf. A111906, A111907.
Sequence in context: A098807 A058218 A140955 this_sequence A064997 A113903 A130261
Adjacent sequences: A111902 A111903 A111904 this_sequence A111906 A111907 A111908
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet Aug 19 2005
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EXTENSIONS
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More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 21 2005
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