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%I #14 Sep 16 2018 04:39:06
%S 3,5,7,41,11,13,113,17,19,2211377674535255285545615254209921,23,313,
%T 66977,29,31,149057,613,37,761,41,43,1013,47,1201,1301,53,1146097
%N Prime numbers arising from A057856.
%C Conjecture: For all pairs of relative prime numbers (x, y) there exists at least one number n = 2^m and one prime number p such that p = x^n + y^n. This sequence shows one case of this conjecture where y = x + 1.
%e a(10)=2211377674535255285545615254209921 because A057856(10)=32 and 2211377674535255285545615254209921 = 10^32 + 11^32 = 100000000000000000000000000000000 + 2111377674535255285545615254209921.
%o (PARI) a(n) = my(k=1); while (!isprime(p=(n+1)^k + n^k), k++); p; \\ _Michel Marcus_, Sep 16 2018
%Y Cf. A057856.
%K nonn,hard
%O 1,1
%A _Tomas Xordan_, Jun 02 2007
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