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%I #32 Aug 05 2020 15:46:19
%S 13,71,181,251,463,521,7321,36473,48157,87421,168527,249341
%N Numbers n such that (37^n - 1)/36 is prime.
%C 7321 is a term found by Richard Fischer in 2004. - _Alexander Adamchuk_, Feb 11 2007
%C No other terms less than 100000. - _Robert Price_, Mar 18 2012
%H H. Dubner, <a href="http://dx.doi.org/10.1090/S0025-5718-1993-1185243-9">Generalized repunit primes</a>, Math. Comp., 61 (1993), 927-930.
%H H. Lifchitz, <a href="http://www.primenumbers.net/Henri/us/MersFermus.htm">Mersenne and Fermat primes field</a>
%H <a href="/index/Pri#primepop">Index to primes in various ranges</a>, form ((k+1)^n-1)/k
%t Select[Prime[Range[100]], PrimeQ[(37^#-1)/36]&]
%o (PARI) is(n)=ispseudoprime((37^n-1)/36) \\ _Charles R Greathouse IV_, Feb 17 2017
%K hard,more,nonn
%O 1,1
%A _Alexander Adamchuk_, Feb 11 2007
%E a(7) from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008
%E a(8)-a(10) from _Robert Price_, Mar 18 2012
%E a(11) from _Paul Bourdelais_, Aug 05 2019
%E a(12) from _Paul Bourdelais_, Aug 04 2020
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