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A070446 a(n) = n^2 mod 24. 2
0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1, 0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1, 0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1, 0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1, 0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1, 0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1, 0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1, 0, 1, 4, 9, 16, 1, 12, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Periodic with period = 12. - Harvey P. Dale, Jun 19 2014

From Jesse Fiedler, Aug 23 2019: (Start)

If a(n) = 1, then n is odd and is not divisible by 3.

For n <= 7919 and a(n)=1, approximately 37.8% of values of n are prime.

For n <= 104729, and a(n)=1, approximately 28.64% of values of n are prime.

(End)

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

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

MATHEMATICA

Table[Mod[n^2, 24], {n, 0, 200}] (* Vladimir Joseph Stephan Orlovsky, Apr 23 2011 *)

PowerMod[Range[0, 100], 2, 24] (* or *) PadRight[{}, 100, {0, 1, 4, 9, 16, 1, 12, 1, 16, 9, 4, 1}] (* Harvey P. Dale, Jun 19 2014 *)

PROG

(PARI) a(n)=n^2%24 \\ Charles R Greathouse IV, Apr 06 2016

CROSSREFS

Sequence in context: A106546 A276191 A007893 * A258682 A070445 A070444

Adjacent sequences:  A070443 A070444 A070445 * A070447 A070448 A070449

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 12 2002

STATUS

approved

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Last modified March 2 09:56 EST 2021. Contains 341746 sequences. (Running on oeis4.)