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%I #16 Sep 08 2022 08:46:14
%S 2,12382,27608,31330,117852
%N Numbers n such that n*9^n + 1 is prime.
%C All terms are even. - _Robert Israel_, Jan 18 2016
%t Select[Range[100000], PrimeQ[# 9^# + 1] &]
%o (PARI) for(n=1,100000, if(isprime(n*9^n+1), print1(n,", ")))
%o (Magma) [n: n in [0..100000] | IsPrime(n*9^n+1)];
%Y Cf. A005849, A006552, A007646, A242176, A242177, A242178, A007647, A242196, A242197, A242198, A242199, A007648.
%K nonn,more,hard
%O 1,1
%A _Tim Johannes Ohrtmann_, Nov 30 2015
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