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Expansion of g.f. x*(1+x+2*x^2+2*x^3+5*x^4+5*x^5-3*x^6+2*x^7-x^8-x^9)/(1-6*x^6-x^12).
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%I #22 Oct 26 2024 09:19:12

%S 0,1,1,2,2,5,5,3,8,11,11,30,30,19,49,68,68,185,185,117,302,419,419,

%T 1140,1140,721,1861,2582,2582,7025,7025,4443,11468,15911,15911,43290,

%U 43290,27379,70669,98048,98048,266765,266765,168717,435482,604199,604199,1643880,1643880,1039681

%N Expansion of g.f. x*(1+x+2*x^2+2*x^3+5*x^4+5*x^5-3*x^6+2*x^7-x^8-x^9)/(1-6*x^6-x^12).

%H G. C. Greubel, <a href="/A116559/b116559.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,6,0,0,0,0,0,1).

%F From _R. J. Mathar_, Nov 28 2008: (Start)

%F a(n) = 6*a(n-6) + a(n-12).

%F G.f.: x*(1+x+2*x^2+2*x^3+5*x^4+5*x^5-3*x^6+2*x^7-x^8-x^9)/(1-6*x^6-x^12).

%F a(6n+1) = A005667(n). (End)

%t CoefficientList[Series[x*(1 + x + 2*x^2 + 2*x^3 + 5*x^4 + 5*x^5 - 3*x^6 + 2*x^7 - x^8 - x^9)/(1 - 6*x^6 - x^12), {x, 0, 50}], x] (* _G. C. Greubel_, Sep 20 2017 *)

%o (PARI) x='x+O('x^50); Vec(x*(1 + x + 2*x^2 + 2*x^3 + 5*x^4 + 5*x^5 - 3*x^6 + 2*x^7 - x^8 - x^9)/(1 - 6*x^6 - x^12)) \\ _G. C. Greubel_, Sep 20 2017

%K nonn,easy,less

%O 0,4

%A _Roger L. Bagula_, Mar 17 2006

%E More terms added by _G. C. Greubel_, Sep 20 2017

%E Better name using given g.f. from _Joerg Arndt_, Oct 26 2024