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%I #25 Nov 16 2014 00:44:25
%S 0,1,4,9,99,412,2633,5093,5632,28233,36780,47084,53572
%N Integers n such that 6 * 7^n + 1 is prime.
%C All terms correspond to verified primes, that is, not merely probable primes.
%C a(14) > 2*10^5.
%e 4 is in this sequence because 6 * 7^4 + 1 = 14407, which is prime.
%t Select[Range[0,200000], PrimeQ[6 * 7^# + 1] &]
%Y Cf. A003307, A002235, A046865, A079906, A001771, A005541, A056725, A046867, A079907.
%Y Cf. A005537, A005538, A005539, A216889, A216890, A247260.
%K nonn,more
%O 1,3
%A _Robert Price_, Nov 14 2014