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A092065 Numbers n such that numerator of Sum_{k=1..n} 1/(prime(k)-k) is prime. 2
2, 3, 4, 5, 7, 14, 21, 22, 26, 27, 32, 43, 51, 58, 62, 65, 82, 131, 148, 207, 229, 249, 257, 320, 334, 386, 423, 440, 481, 747, 823, 1181, 1314, 1915, 2025, 2269 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Note that the definition here is subtly different from that of A092063.

LINKS

Table of n, a(n) for n=1..36.

MAPLE

count:= 0:

S:= 0: p:= 0;

for n from 1 to 2500 do

  p:= nextprime(p);

  S:= S + 1/(p - n);

  if isprime(numer(S)) then

    count:= count+1;

    A[count]:= n;

  fi

od:

seq(A[i], i=1..count); # Robert Israel, Sep 07 2014

MATHEMATICA

f=0; Do[ p=Prime[n]; f=f+1/(p-n); g=Numerator[f]; If[ PrimeQ[g], Print[n]], {n, 1, 500} ]

PROG

(PARI) S=1; for(n=2, 100, S=S+1/(prime(n)-n); if(isprime(numerator(S)), print1(n, ", "))) \\ Edward Jiang, Sep 08 2014

CROSSREFS

Cf. A092066.

Sequence in context: A125707 A039060 A278442 * A044955 A044817 A297136

Adjacent sequences:  A092062 A092063 A092064 * A092066 A092067 A092068

KEYWORD

nonn

AUTHOR

Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Feb 20 2004; corrected Apr 24 2006

EXTENSIONS

Sequence and Mathematica program corrected by Alexander Adamchuk, Jul 29 2007

a(30)-a(34) from Vincenzo Librandi, Nov 26 2012

a(35) and a(36) from Robert Israel, Sep 07 2014

STATUS

approved

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Last modified January 16 23:44 EST 2019. Contains 319206 sequences. (Running on oeis4.)