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Numbers k such that k*6^k + 1 is prime.
9

%I #18 Sep 08 2022 08:46:08

%S 1,2,91,185,387,488,747,800,9901,10115,12043,13118,30981,51496

%N Numbers k such that k*6^k + 1 is prime.

%H G. Loeh, <a href="http://guenter.loeh.name/gc/status.html">Generalized Cullen primes</a>

%t Select[Range[1500], PrimeQ[# 6^# + 1] &]

%o (Magma) [n: n in [0..1500] | IsPrime(n*6^n+1)];

%o (PARI) is(n)=ispseudoprime(n*6^n+1) \\ _Charles R Greathouse IV_, Feb 17 2017

%Y Cf. numbers n such that n*k^n + 1 is prime: A005849 (k=2), A006552 (k=3), A007646 (k=4), this sequence (k=6), A242177 (k=7), A242178 (k=8), A007647 (k=10), A242196 (k=12), A242197 (k=14), A242198 (k=15), A242199 (k=16), A007648 (k=18).

%K nonn,more

%O 1,2

%A _Vincenzo Librandi_, May 08 2014

%E a(9)-a(14) from Loeh's list (see Links) - _Bruno Berselli_, May 08 2014