A036130 - OEIS

%I #25 Sep 08 2022 08:44:52

%S 1,2,4,8,16,32,3,6,12,24,48,35,9,18,36,11,22,44,27,54,47,33,5,10,20,

%T 40,19,38,15,30,60,59,57,53,45,29,58,55,49,37,13,26,52,43,25,50,39,17,

%U 34,7,14,28,56,51,41,21,42,23,46

%N a(n) = 2^n mod 61.

%D I. M. Vinogradov, Elements of Number Theory, pp. 220 ff.

%H Muniru A Asiru, <a href="/A036130/b036130.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_31">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,1).

%F a(n) = a(n+60). - _R. J. Mathar_, Jun 04 2016

%F a(n) = a(n-1) - a(n-30) + a(n-31). - _G. C. Greubel_, Oct 17 2018

%p [ seq(primroot(ithprime(i))^j mod ithprime(i),j=0..100) ];

%t PowerMod[2, Range[0, 100], 61] (* _G. C. Greubel_, Oct 17 2018 *)

%o (PARI) a(n)=lift(Mod(2,61)^n) \\ _Charles R Greathouse IV_, Mar 22 2016

%o (Magma) [Modexp(2, n, 61): n in [0..100]]; // _G. C. Greubel_, Oct 17 2018

%o (GAP) a:=List([0..70],n->PowerMod(2,n,61));; Print(a); # _Muniru A Asiru_, Jan 29 2019

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_