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%I #28 Aug 17 2021 02:17:20
%S 1,11,121,323,117283,432091,4132384531,15516834659,15941429747,
%T 98953554491,3272831195051,7362974489179,26306805687881,
%U 33869035218491,280980898827691
%N Numbers k that divide 2^k + 9.
%C No other terms below 10^15. Some larger terms: 53496121130110340001650284048539458491, 136243118444105327963550175410279542214992801356720577. - _Max Alekseyev_, Sep 29 2016
%H OEIS Wiki, <a href="/wiki/2^n mod n">2^n mod n</a>
%e 2^11 + 9 = 2057 is divisible by 11. Thus 11 is a term of this sequence.
%p select(n -> 9 + 2 &^ n mod n = 0, [$1..10^6]); # _Robert Israel_, Aug 04 2014
%o (PARI) for(n=1,10^9, if(Mod(2,n)^n==-9, print1(n,", "); ); );
%Y Cf. A051447, A188165, A245594, A245319, A245318, A244673.
%K nonn,more,hard
%O 1,2
%A _Derek Orr_, Aug 04 2014
%E a(7)-a(10) from _Lars Blomberg_, Nov 05 2014
%E a(11)-a(15) from _Max Alekseyev_, Sep 29 2016
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