A224470 - OEIS

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A224470

Numbers k such that 7^k - k is prime.

%I #26 Dec 22 2024 10:03:10

%S 2,6,8,12,44,48,512,1088,1104,6038

%N Numbers k such that 7^k - k is prime.

%C a(11) > 92000. - _Giovanni Resta_, Apr 08 2013

%C a(11) > 2*10^5. - _Robert Price_, Feb 11 2014

%o (PARI) forstep(n=2,10^4,2,if(ispseudoprime(7^n-n),print1(n,", "))); /* _Joerg Arndt_, Apr 07 2013 */

%Y Cf. A048744, A058037, A057908, A058046, A058829, A224468.

%K nonn,more

%O 1,1

%A _Alex Ratushnyak_, Apr 06 2013