%I #11 Jun 08 2021 02:22:46
%S 1,3,9,57,171,1467,13131,27873,32547,97641,249489,261633,784899,
%T 1218897,1255347,2140353,4971027,8246019,9961491,12914001,14913081,
%U 15915483,23159043,23851593,24738057,29884473,40666707,83512353,127938537
%N Numbers k such that k^3 divides 8^(k^2) + 1.
%C 3 divides a(n) for n > 1.
%t Select[Range[5*10^6], Mod[ 8^(#^2)+1, #^3]==0 &] (* _G. C. Greubel_, Jan 18 2018 *)
%Y Cf. A127263 (numbers k such that k^3 divide 2^(k^2)+1).
%Y Cf. A128677 (least k > p such that (k*p)^3 divides (p-1)^(k*p)^2+1, where p = prime(n) > 2).
%Y Cf. A128678, A128679, A128680, A128682, A128683, A128684, A128685.
%K hard,nonn
%O 1,2
%A _Alexander Adamchuk_, Mar 31 2007
%E More terms from _Ryan Propper_, Jan 13 2008
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