login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Period 10: repeat [-1, 1, -3, 7, -5, 3, -7, 9, -9, 5].
0

%I #28 Dec 12 2023 08:24:04

%S -1,1,-3,7,-5,3,-7,9,-9,5,-1,1,-3,7,-5,3,-7,9,-9,5,-1,1,-3,7,-5,3,-7,

%T 9,-9,5,-1,1,-3,7,-5,3,-7,9,-9,5,-1,1,-3,7,-5,3,-7,9,-9,5,-1,1,-3,7,

%U -5,3,-7,9,-9,5,-1,1,-3,7,-5,3,-7,9,-9,5,-1,1,-3,7,-5,3,-7,9,-9,5,-1,1,-3,7,-5,3,-7,9,-9,5,-1,1,-3

%N Period 10: repeat [-1, 1, -3, 7, -5, 3, -7, 9, -9, 5].

%C It appears that abs(a(n)) = abs(A001469(n+1)) mod 10.

%C It also appears that abs(a(n)) = abs(A228767(n+4)) mod 10. - _Michel Marcus_, Sep 04 2013

%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (-1,-1,-1,-1,-1,-1,-1,-1,-1).

%F G.f.: ( -1-3*x^2+4*x^3+2*x^5-5*x^6-5*x^8-x^4+4*x^7 ) / ( (1+x)*(1+x+x^2+x^3+x^4)*(x^4-x^3+x^2-x+1) ). - _R. J. Mathar_, Oct 08 2011

%F a(n) = - Sum_{k=1..9} a(n-k). - _Wesley Ivan Hurt_, May 27 2021

%t PadRight[{},120,{-1,1,-3,7,-5,3,-7,9,-9,5}] (* _Harvey P. Dale_, Mar 03 2023 *)

%Y Cf. A001469, A228767.

%K sign,easy,less

%O 0,3

%A _Paul Curtz_, Aug 11 2008