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%I #12 Aug 01 2023 19:39:14
%S 2,3,5,181,40087,251737
%N Primes p such that gcd(p, prime(p)^2 - 1) does not equal 1.
%C No further terms up to 41161739. - _Harvey P. Dale_, Dec 23 2011
%C No further terms up to 250000000. - _Sean A. Irvine_, Aug 01 2023
%e 5 belongs in the sequence because gcd(5, P_5^2 -1) = gcd(5, 120) = 5.
%t Do[ If[ GCD[ Prime[n], Prime[ Prime[n]]^2 - 1] != 1, Print[ Prime[n]] ], {n, 1, 10^6} ]
%Y Cf. A064830.
%K nonn,more
%O 1,1
%A _Robert G. Wilson v_, Oct 26 2001
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