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A122521 Recursion: a(n) = a(n - 6) + a(n - 8). 2

%I #18 Apr 06 2018 11:44:18

%S 1,1,1,1,1,1,1,1,2,2,2,2,2,2,3,3,4,4,4,4,5,5,7,7,8,8,9,9,12,12,15,15,

%T 17,17,21,21,27,27,32,32,38,38,48,48,59,59,70,70,86,86,107,107,129,

%U 129,156,156,193,193,236,236,285,285,349,349,429,429,521,521,634,634,778,778

%N Recursion: a(n) = a(n - 6) + a(n - 8).

%H G. C. Greubel, <a href="/A122521/b122521.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,1,0,1).

%F a(n) = a(n - 6) + a(n - 8).

%F G.f.: -x*(x+1)*(x^2-x+1)*(x^2+x+1)/(x^8+x^6-1). - _Colin Barker_, Oct 19 2012

%t Rest[CoefficientList[Series[-x*(x + 1)*(x^2 - x + 1)*(x^2 + x + 1)/(x^8 + x^6 - 1), {x, 0, 50}], x]] (* _G. C. Greubel_, May 01 2017 *)

%o (PARI) a(n)=([0,1,0,0,0,0,0,0; 0,0,1,0,0,0,0,0; 0,0,0,1,0,0,0,0; 0,0,0,0,1,0,0,0; 0,0,0,0,0,1,0,0; 0,0,0,0,0,0,1,0; 0,0,0,0,0,0,0,1; 1,0,1,0,0,0,0,0]^(n-1)*[1;1;1;1;1;1;1;1])[1,1] \\ _Charles R Greathouse IV_, Oct 03 2016

%o (PARI) x='x+O('x^50); Vec(-x*(x+1)*(x^2-x+1)*(x^2+x+1)/(x^8+x^6-1)) \\ _G. C. Greubel_, May 01 2017

%K nonn,easy

%O 1,9

%A _Roger L. Bagula_, Sep 16 2006

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