A266973 a(n) = 4^n mod 17.
1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16, 13, 1, 4, 16
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (0,0,0,1).
Crossrefs
Programs
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Magma
[Modexp(4, n, 17): n in [0..100]];
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Maple
A266973:=n->power(4,n) mod 17: seq(A266973(n), n=0..100); # Wesley Ivan Hurt, Jun 29 2016
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Mathematica
PowerMod[4, Range[0, 100], 17]
Formula
G.f.: (1+4*x+16*x^2+13*x^3)/(1-x^4).
a(n) = a(n-4) for n>3.
From Wesley Ivan Hurt, Jun 29 2016: (Start)
a(n) = (34 - 3*(5 + 3*I)*I^(-n) - 3*(5 - 3*I)*I^n)/4 where I=sqrt(-1).
a(n) = (17 - 15*cos(n*Pi/2) - 9*sin(n*Pi/2))/2. (End)
Comments