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A070462
a(n) = n^2 mod 40.
3
0, 1, 4, 9, 16, 25, 36, 9, 24, 1, 20, 1, 24, 9, 36, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16, 25, 36, 9, 24, 1, 20, 1, 24, 9, 36, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16, 25, 36, 9, 24, 1, 20, 1, 24, 9, 36, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16, 25, 36, 9, 24, 1, 20, 1, 24, 9, 36, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16
OFFSET
0,3
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, 1).
FORMULA
a(n) = a(n-20). - G. C. Greubel, Mar 25 2016
MATHEMATICA
Table[Mod[n^2, 40], {n, 0, 200}] (* Vladimir Joseph Stephan Orlovsky, Apr 27 2011 *)
PowerMod[Range[0, 90], 2, 40] (* Harvey P. Dale, Oct 20 2013 *)
PROG
(PARI) a(n)=n^2%40 \\ Charles R Greathouse IV, Apr 06 2016
CROSSREFS
Sequence in context: A070465 A070464 A070463 * A070461 A070460 A070459
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 12 2002
STATUS
approved