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a(n) = n^2 mod 31.
5

%I #14 Dec 18 2023 12:48:27

%S 0,1,4,9,16,25,5,18,2,19,7,28,20,14,10,8,8,10,14,20,28,7,19,2,18,5,25,

%T 16,9,4,1,0,1,4,9,16,25,5,18,2,19,7,28,20,14,10,8,8,10,14,20,28,7,19,

%U 2,18,5,25,16,9,4,1,0,1,4,9,16,25,5,18,2,19,7,28,20,14,10,8,8,10,14,20

%N a(n) = n^2 mod 31.

%H G. C. Greubel, <a href="/A070453/b070453.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 (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, 0, 0, 1).

%F a(n) = a(n-31). - _G. C. Greubel_, Mar 24 2016

%t Table[Mod[n^2,31],{n,0,200}] (* _Vladimir Joseph Stephan Orlovsky_, Apr 27 2011 *)

%o (PARI) a(n)=n^2%31 \\ _Charles R Greathouse IV_, Apr 06 2016

%Y Cf. A070450, A070451.

%K nonn,easy

%O 0,3

%A _N. J. A. Sloane_, May 12 2002