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%I #21 May 27 2024 02:40:51
%S 1,2,-4,4,-2,-1,-1,-2,4,-4,2,1,1,2,-4,4,-2,-1,-1,-2,4,-4,2,1,1,2,-4,4,
%T -2,-1,-1,-2,4,-4,2,1,1,2,-4,4,-2,-1,-1,-2,4,-4,2,1
%N Palindromic period of length 12: repeat 1,2,-4,4,-2,-1,-1,-2,4,-4,2,1.
%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,-1)
%F a(n) == A154811(n) (mod 9).
%F a(n) = ( (2*A154811(n)) mod 9 ) - A154811(n).
%F G.f.: -(x-1)*(x^4+3*x^3-x^2+3*x+1) / ( (1+x^2)*(x^4-x^2+1) ). - _R. J. Mathar_, Mar 08 2011
%t PadRight[{},50,{1,2,-4,4,-2,-1,-1,-2,4,-4,2,1}] (* _Harvey P. Dale_, May 29 2021 *)
%Y Cf. A156283.
%K easy,sign
%O 0,2
%A _Paul Curtz_, Feb 08 2009