The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #23 Nov 03 2021 17:41:26
%S 4,6,22420,27636,27850,28986,31168,586020
%N Numbers n such that 11^n - 2 is prime.
%C Corresponding primes are in A133858.
%C 11^22420-2 is a 23349-digit probable prime found with PrimeForm.
%C a(8) > 10^5. - _Robert Price_, Mar 26 2014
%C a(4) through a(7) also correspond to probable primes. - _Robert Price_, Mar 27 2014
%o (PARI) is(n)=ispseudoprime(11^n-2) \\ _Charles R Greathouse IV_, May 22 2017
%Y Cf. A133858, A130652.
%K hard,nonn,more
%O 1,1
%A _Rick L. Shepherd_, Sep 30 2007
%E a(4)-a(7) from _Robert Price_, Mar 26 2014
%E a(8) from _Paul Bourdelais_, Nov 03 2021