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A092062
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Numbers n such that numerator of (sum(i=1,n,1/prime(i)^2)) is prime.
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1
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OFFSET
| 1,1
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COMMENTS
| a(6)>447 for a(6) the numerator has more than 2673 digits
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FORMULA
| Numbers n such that numerator of (sum(i=1, n, 1/prime(i)^2)) is prime
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EXAMPLE
| 1/2^2=1/4
1/2^2 +1/3^2 = 13/36 and 13 is prime than a(1)=2
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PROG
| (PARI) sm(n)= s=0; for(i=1, n, s=s+1/(prime(i)^2)); return(s); for (i=1, 400, if(isprime(numerator(sm(i))), print1(i, ", ")))
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CROSSREFS
| Sequence in context: A082969 A173592 A018227 * A134251 A055260 A180591
Adjacent sequences: A092059 A092060 A092061 * A092063 A092064 A092065
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KEYWORD
| hard,nonn
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AUTHOR
| mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Feb 20 2004
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EXTENSIONS
| a(6) from Alexander Adamchuk (alex(AT)kolmogorov.com), Sep 16 2010
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