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 A010675 Period 2: repeat (0,4). 1
 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0, 4, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Index entries for linear recurrences with constant coefficients, signature (0,1). FORMULA a(n) = 2*(1-(-1)^n); a(n) = 4*(n mod 2) - Paolo P. Lava, Oct 20 2006 O.g.f.: -2/(1+x)-2/(x-1). - R. J. Mathar, Feb 19 2008 a(n) = 4*(1+floor((n+1)/2)-ceiling((n+1)/2)). - Wesley Ivan Hurt, May 21 2013 a(n) = 4*cos( Pi*(n+1)/2 )^2. - Wesley Ivan Hurt, May 21 2013 PROG (MAGMA) &cat [[0, 4]^^50]; // Bruno Berselli, Dec 10 2015 (PARI) a(n)=n%2*4 \\ Charles R Greathouse IV, Jul 23 2016 CROSSREFS Sequence in context: A230031 A019920 A246130 * A035673 A035638 A292142 Adjacent sequences:  A010672 A010673 A010674 * A010676 A010677 A010678 KEYWORD nonn,easy AUTHOR STATUS approved

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Last modified May 15 17:11 EDT 2021. Contains 343920 sequences. (Running on oeis4.)