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A070512
a(n) = n^4 mod 7.
2
0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2, 4, 4, 2, 1, 0, 1, 2
OFFSET
0,3
COMMENTS
Equivalently: n^(4*m + 4) mod 7. - G. C. Greubel, Apr 01 2016
FORMULA
From G. C. Greubel, Apr 01 2016: (Start)
a(n) = a(n-7).
G.f.: x*(1 +2*x +4*x^2 +2*x^4 + x^5)/(1 - x^7). (End)
MATHEMATICA
PowerMod[Range[0, 100], 4, 7] (* G. C. Greubel, Apr 01 2016 *)
PROG
(SageMath) [power_mod(n, 4, 7)for n in range(0, 101)] # Zerinvary Lajos, Oct 30 2009
(Magma) [Modexp(n, 4, 7): n in [0..100]]; // Vincenzo Librandi, Apr 02 2016
(PARI) a(n)=n^4%7 \\ Charles R Greathouse IV, Apr 06 2016
CROSSREFS
Sequence in context: A058923 A107500 A108620 * A156346 A156283 A126123
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 13 2002
STATUS
approved