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A091816
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Numbers n such that numerator of sum(i=1,n,(i+1)/i) is prime.
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0
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1, 2, 3, 4, 8, 14, 15, 17, 19, 21, 22, 27, 28, 31, 55, 59, 80, 108, 114, 126, 199, 225, 248, 316, 352, 406, 467, 601, 875
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OFFSET
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1,2
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LINKS
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PROG
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(PARI) ss(n)=sum(i=1, n, (i+1)/i); for (i=1, 1000, if(isprime(numerator(ss(i))), print1(i, ", ")))
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CROSSREFS
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KEYWORD
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hard,nonn
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AUTHOR
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Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 07 2004
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STATUS
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approved
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