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a(n) = 2^n mod 3*n
1

%I #16 Sep 08 2022 08:45:57

%S 2,4,8,4,2,10,2,16,26,4,2,28,2,4,8,16,2,28,2,16,8,4,2,64,32,4,80,16,2,

%T 64,2,64,8,4,53,28,2,4,8,16,2,64,2,16,107,4,2,64,128,124,8,16,2,82,98,

%U 88,8,4,2,136,2,4,134,64,32,64,2,16,8,184,2,136,2,4

%N a(n) = 2^n mod 3*n

%H Vincenzo Librandi, <a href="/A191561/b191561.txt">Table of n, a(n) for n = 1..1000</a>

%t Table[PowerMod[2, n, 3 n], {n, 100}] (* _Vincenzo Librandi_, Jun 12 2016 *)

%o (Magma) [Modexp(2, n, 3*n): n in [1..100]]; // _Vincenzo Librandi_, Jun 12 2016

%o (PARI) a(n)=lift(Mod(2,3*n)^n) \\ _Charles R Greathouse IV_, Dec 27 2011

%Y Cf. A083528, A083529, A083530.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Jul 31 2011