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Numbers k such that k^3 divides 18^(k^2) + 1.
9

%I #7 Jun 06 2021 09:03:14

%S 1,19,397841,1152331,3566699,24128658809,74683110361,216316727651,

%T 1339092172657,7967201553697

%N Numbers k such that k^3 divides 18^(k^2) + 1.

%C 19 divides a(n) for n > 1.

%Y Cf. A127263 (k^3 divides 2^(k^2) + 1).

%Y Cf. A128678, A128679, A128680, A128681, A128682, A128683, A128684, A128685.

%Y Cf. A177813, A177814, A177816, A177817, A177818, A177819, A177820.

%Y Cf. A128677 (least k > p such that (k*p)^3 divides (p-1)^(k*p)^2+1, where p = prime(n) > 2).

%K more,nonn

%O 1,2

%A _Alexander Adamchuk_, May 14 2010

%E a(6)-a(10) from _Max Alekseyev_, May 16 2010