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A136365 Numbers n such that A075986(n) is prime. 6
1, 171, 210 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..3.

MATHEMATICA

f=1; Do[ p=Prime[n]; f=f + 1/p^2; g=Numerator[ f ]; If[ PrimeQ[ g ], Print[ {n, g} ] ], {n, 1, 210} ]

CROSSREFS

Cf. A075986 = Numerator of 1+1/p(1)^2+ ... + 1/p(n)^2, where p(k) = k-th prime. Cf. A024528, A125707. Cf. A136366, A136367, A136368, A136369, A136370, A136371.

Sequence in context: A045149 A031511 A101273 * A031900 A120819 A115078

Adjacent sequences:  A136362 A136363 A136364 * A136366 A136367 A136368

KEYWORD

bref,hard,more,nonn

AUTHOR

Alexander Adamchuk, Dec 27 2007

STATUS

approved

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Last modified December 16 07:12 EST 2018. Contains 318158 sequences. (Running on oeis4.)