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Search: id:A117102
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| A117102 |
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Least n such that nextprime(p*n)>p*nextprime(n) where p traversing prime numbers (if p is prime then nextprime(p)=p). |
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+0
1
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| 4, 16, 18, 42, 126, 126, 136, 70, 58, 292, 822, 1872, 1446, 1008, 3318, 2026, 2280, 2842, 7726, 17922, 2136, 5022, 20142, 17550, 19540, 68898, 59082, 18792, 90006, 136540, 246888, 392382, 197088, 144060, 819898, 137956, 1555162, 291198, 909772
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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A(n)+1 is always prime ? A(n) is always even ?
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EXAMPLE
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for p=2 least n such than f(2*n)>2*f(n) and n is composite is 4=a(1)
for p=3 least n such than f(3*n)>3*f(n) and n is composite is 16=a(2)
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PROGRAM
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(PARI) f(n)=nextprime(n); g(n, a)=for(i=1, a, if(f(n*i)>f(n)*f(i) && !isprime(i), return(i))); forprime (i=1, 150, print1(g(i, 5000000), ", "))
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CROSSREFS
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Sequence in context: A037409 A034121 A139719 this_sequence A077476 A146510 A032827
Adjacent sequences: A117099 A117100 A117101 this_sequence A117103 A117104 A117105
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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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