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%I #27 Sep 17 2024 14:17:04
%S 0,1,2,3,4,9,10,13,15,24
%N Integers k such that k^k + k^2 + 2*k + 1 is prime.
%C The next prime (if any) is unknown, but it must exceed 2000^2000 + 2000^2 + 2*2000 + 1 (a 6603-digit number).
%C a(11) > 15000, if it exists. - _Michael S. Branicky_, Sep 17 2024
%e If k = 2, then k^k + k^2 + k*2 + 1 = 2^2 + 2^2 + 2*2 + 1 = 13, which is prime.
%Y Cf. A058912, A187605, A231712.
%K nonn,more,hard,changed
%O 1,3
%A _Marco Ripà_, Sep 10 2022