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Search: id:A117098
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| A117098 |
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Numbers n such that nextprime(5*n)<5*nextprime(n) (if p is prime then nextprime(p)=p). |
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+0
1
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| 1, 4, 6, 8, 9, 10, 12, 14, 15, 16, 20, 21, 22, 24, 25, 26, 27, 30, 32, 33, 34, 35, 36, 38, 39, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 62, 63, 64, 65, 66, 68, 69, 70, 74, 75, 76, 77, 80, 81, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 98, 99, 100
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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denote f(x)=nextprime(x) let A(p)={n/f(p*n)<f(p)*f(n)} and A(q)={n/f(q*n)<f(q)*f(n)} (q,p are prime) if q<p all terms of A(q) are in A(p). if B(p)={n/f(p*n)>f(p)*f(n)} I conjuctured that when p --> infinity, A(p) = All composite positive integers when p --> infinity, B(p) = All primes numbers
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EXAMPLE
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nextprime(5*4)=23 and nextprime(5)*nextprime(4)=5*5=25 then 4 is member because 23<15
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PROGRAM
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(PARI) for(i=1, 100, if(nextprime(5*i)<nextprime(5)*nextprime(i), print1(i, ", ")))
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CROSSREFS
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Adjacent sequences: A117095 A117096 A117097 this_sequence A117099 A117100 A117101
Sequence in context: A046352 A046355 A050655 this_sequence A077136 A098216 A063806
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KEYWORD
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easy,nonn
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AUTHOR
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Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 18 2006
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