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First differences of the dying rabbits sequence A000044.
1

%I #17 Jun 24 2023 12:22:29

%S 0,0,1,1,2,3,5,8,13,21,34,55,88,143,231,373,603,974,1574,2543,4109,

%T 6639,10727,17332,28004,45248,73109,118126,190862,308385,498273,

%U 805084,1300814,2101789,3395964,5487026,8865658,14324680,23145090,37396661,60423625

%N First differences of the dying rabbits sequence A000044.

%H <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1).

%F G.f.: x^3(1 + x + x^2 + x^3 + x^4)(1 - x + x^2 - x^3 + x^4)/(1 - x - x^3 - x^5 - x^7 - x^9 - x^11). - _Charles R Greathouse IV_, Jun 19 2011

%t A000044 = CoefficientList[Series[1/(1 - z - z^3 - z^5 - z^7 - z^9 - z^11), {z, 0, 200}], z]; GetDiff[seq_List] := Drop[seq, 1] - Drop[seq, -1]; A191869 = GetDiff[A000044]

%o (PARI) A191869_list=Vec((-x^11-x^9-x^7-x^5-x^3)/(x^11+x^9+x^7+x^5+x^3+x-1)+O(x^99)) /* returns a list of the first 96 nonzero terms, a(3)...a(99) */

%o (PARI) A191869(n)=polcoeff((1+x^2+x^4+x^6+x^8)/(1-x-x^3-x^5-x^7-x^9-x^11+O(x^max(1,n-2))),n-3) \\ _M. F. Hasler_, Jun 19 2011

%Y Cf. A000044.

%K nonn,easy

%O 1,5

%A _Vladimir Joseph Stephan Orlovsky_, Jun 18 2011