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A187890 a(1)=0, a(2)=4, a(n)=a(n-1)+a(n-2)-1. 4

%I #26 Jan 06 2024 01:00:10

%S 0,4,3,6,8,13,20,32,51,82,132,213,344,556,899,1454,2352,3805,6156,

%T 9960,16115,26074,42188,68261,110448,178708,289155,467862,757016,

%U 1224877,1981892,3206768,5188659,8395426,13584084,21979509,35563592,57543100

%N a(1)=0, a(2)=4, a(n)=a(n-1)+a(n-2)-1.

%H Vincenzo Librandi, <a href="/A187890/b187890.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,-1).

%F G.f.: -x^2*(-4+5*x) / ( (x-1)*(x^2+x-1) ). - _R. J. Mathar_, Mar 15 2011

%F a(n) = 1+A001060(n-2), n>2. - _R. J. Mathar_, Mar 15 2011

%F a(n) - a(n-1) = A013655(n-4). - _R. J. Mathar_, Jun 19 2021

%t Join[{a = 0, b = 4}, Table[c = a+b-1; a=b; b=c, {n, 100}]]

%t LinearRecurrence[{2, 0, -1}, {0, 4, 3}, 40] (* _Harvey P. Dale_, Sep 25 2013 *)

%t CoefficientList[Series[(-x (-4 + 5 x))/((x - 1) (x^2 + x - 1)), {x, 0, 40}], x] (* _Vincenzo Librandi_, Sep 26 2013 *)

%Y Cf. A000071, A001611, A001612.

%K nonn,easy

%O 1,2

%A _Vladimir Joseph Stephan Orlovsky_, Mar 15 2011

%E Definition adapted to offset by _Georg Fischer_, Jun 19 2021

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)