A094920 - OEIS

%I #13 May 19 2020 19:13:09

%S 0,0,1,0,1,0,1,0,4,6,1,0,1,6,1,0,1,0,1,16,10,6,1,0,6,6,13,16,1,6,1,0,

%T 31,6,11,0,1,6,31,16,1,0,1,24,31,6,1,0,29,6,31,0,1,0,11,48,31,6,1,36,

%U 1,6,31,0,1,12,1,20,31,16,1,0,1,6,31,4,39,6,1,16,40,6,1,0,16,6,31,64,1,36,57,64

%N a(n) = (5^n-1)/4 mod n.

%H Antti Karttunen, <a href="/A094920/b094920.txt">Table of n, a(n) for n = 1..16384</a>

%H Antti Karttunen, <a href="/A094920/a094920.txt">Data supplement: n, a(n) computed for n = 1..65537</a>

%t Table[Mod[(5^n-1)/4,n],{n,100}] (* _Harvey P. Dale_, Sep 20 2016 *)

%o (PARI) A094920(n) = lift(Mod((5^n-1)/4,n)); \\ _Antti Karttunen_, May 19 2020

%Y Cf. A003463.

%K nonn

%O 1,9

%A _N. J. A. Sloane_, Jun 18 2004