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A091816 Numbers n such that numerator of sum(i=1,n,(i+1)/i) is prime. 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
PROG
(PARI) ss(n)=sum(i=1, n, (i+1)/i); for (i=1, 1000, if(isprime(numerator(ss(i))), print1(i, ", ")))
CROSSREFS
Sequence in context: A091415 A166342 A361502 * A266400 A274914 A100993
KEYWORD
hard,nonn
AUTHOR
Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 07 2004
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)