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a(n) = T(2n, n+2), T given by A027935.
1

%I #20 Sep 08 2022 08:44:49

%S 1,16,92,365,1204,3588,10093,27476,73440,194345,511576,1342936,

%T 3520457,9222440,24151764,63238773,165571628,433484476,1134891605,

%U 2971201740,7778726776

%N a(n) = T(2n, n+2), T given by A027935.

%H G. C. Greubel, <a href="/A027938/b027938.txt">Table of n, a(n) for n = 2..1000</a>

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (7,-19,26,-19,7,-1).

%F G.f.: x^2*(1+9*x-x^2-x^3) / ((1-x)^4*(1-3*x+x^2)). - _Colin Barker_, Dec 10 2015

%F a(n) = Fibonacci(2*n+5) - (4*n^3 + 6*n^2 + 14*n + 15)/3. - _G. C. Greubel_, Sep 28 2019

%p with(combinat); seq(fibonacci(2*n+5) - (4*n^3 +6*n^2 +14*n +15)/3, n=2..30); # _G. C. Greubel_, Sep 28 2019

%t Table[Fibonacci[2*n+5] -(4*n^3 +6*n^2 +14*n +15)/3, {n,2,30}] (* _G. C. Greubel_, Sep 28 2019 *)

%o (PARI) vector(30, n, my(m=n+1); fibonacci(2*m+5) - (4*m^3 +6*m^2 +14*m +15)/3) \\ _G. C. Greubel_, Sep 28 2019

%o (Magma) [Fibonacci(2*n+5) - (4*n^3 +6*n^2 +14*n +15)/3: n in [2..30]]; // _G. C. Greubel_, Sep 28 2019

%o (Sage) [fibonacci(2*n+5) - (4*n^3 +6*n^2 +14*n +15)/3 for n in (2..30)] # _G. C. Greubel_, Sep 28 2019

%o (GAP) List([2..30], n-> Fibonacci(2*n+5) - (4*n^3 +6*n^2 +14*n +15)/3 ); # _G. C. Greubel_, Sep 28 2019

%Y Cf. A000045, A027935.

%K nonn,easy

%O 2,2

%A _Clark Kimberling_