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%I #13 Jun 06 2021 15:52:34
%S 1,171,210,550,1445,1809,2176,2719
%N Numbers k such that A075986(k) is prime.
%t f=1; Do[ p=Prime[n]; f=f + 1/p^2; g=Numerator[ f ]; If[ PrimeQ[ g ], Print[ {n, g} ] ], {n, 1, 210} ]
%Y Cf. A075986 (numerator of 1 + 1/p(1)^2 + ... + 1/p(n)^2, where p(k) = prime(k)).
%Y Cf. A024528, A125707.
%Y Cf. A136366, A136367, A136368, A136369, A136370, A136371.
%K nonn,hard,more
%O 1,2
%A _Alexander Adamchuk_, Dec 27 2007
%E a(4)-a(8) from _Robert Price_, Aug 26 2019
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