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Positive integers n such that n | (5^n + 6).
7

%I #34 Oct 17 2016 10:21:14

%S 1,11,341,581337017,7202608727,27146455379,1358496201131,

%T 9843739213499,172392038905691

%N Positive integers n such that n | (5^n + 6).

%C No other terms below 10^15. - _Max Alekseyev_, Oct 17 2016

%F A066603(a(n)) = a(n) - 6 for n > 1.

%e 5^11 + 6 = 48828131 = 11 * 4438921, so 11 is a term.

%o (PARI) isok(n) = Mod(5, n)^n == -6; \\ _Michel Marcus_, Oct 10 2016

%Y Cf. A066603.

%Y Cf. Solutions to 5^n == k (mod n): this sequence (k=-6), A015891 (k=-5), A123047 (k=-4), A123052 (k=-3), A123062 (k=-2), A015951 (k=-1), A067946 (k=1), A124246 (k=2), A123061 (k=3), A125949 (k=4), A123091 (k=5), A277350 (k=6).

%K nonn,more

%O 1,2

%A _Seiichi Manyama_, Oct 10 2016

%E a(5)-a(9) from _Max Alekseyev_, Oct 17 2016