

A070540


a(n) = n^4 mod 21.


1



0, 1, 16, 18, 4, 16, 15, 7, 1, 9, 4, 4, 9, 1, 7, 15, 16, 4, 18, 16, 1, 0, 1, 16, 18, 4, 16, 15, 7, 1, 9, 4, 4, 9, 1, 7, 15, 16, 4, 18, 16, 1, 0, 1, 16, 18, 4, 16, 15, 7, 1, 9, 4, 4, 9, 1, 7, 15, 16, 4, 18, 16, 1, 0, 1, 16, 18, 4, 16, 15, 7, 1, 9, 4, 4, 9, 1, 7, 15, 16, 4, 18, 16, 1, 0, 1, 16, 18
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OFFSET

0,3


COMMENTS



LINKS

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).


FORMULA

a(21*n) = 0.
a(n+21) = a(n). (End)


MATHEMATICA



PROG

(Sage) [power_mod(n, 4, 21)for n in range(0, 88)] # Zerinvary Lajos, Oct 31 2009


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



