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T(2n+3,n), where T is the array in A055830.
2

%I #15 Jan 22 2020 09:42:33

%S 3,15,73,361,1806,9122,46425,237721,1223365,6321965,32784830,

%T 170528190,889291352,4648068192,24342384337,127707864849,671047979300,

%U 3531026714720,18603737992455,98129545962855,518149580437560

%N T(2n+3,n), where T is the array in A055830.

%H G. C. Greubel, <a href="/A055837/b055837.txt">Table of n, a(n) for n = 0..500</a>

%F Conjecture: 5*n*(n+2)*(11*n-4)*a(n) +(-242*n^3-330*n^2+29*n+42)*a(n-1) -3*(3*n-1)*(11*n+7)*(3*n-2)*a(n-2)=0. - _R. J. Mathar_, Mar 13 2016

%p with(combinat);

%p T:= proc(n, k) option remember;

%p if k<0 or k>n then 0

%p elif k=0 then fibonacci(n+1)

%p elif n=1 and k=1 then 0

%p else T(n-1, k-1) + T(n-1, k) + T(n-2, k)

%p fi; end:

%p seq(T(2*n+3, n), n=0..30); # _G. C. Greubel_, Jan 21 2020

%t T[n_, k_]:= T[n, k]= If[k<0 || k>n, 0, If[k==0, Fibonacci[n+1], If[n==1 && k==1, 0, T[n-1, k-1] + T[n-1, k] + T[n-2, k]]]]; Table[T[2*n+3, n], {n,0,30}] (* _G. C. Greubel_, Jan 21 2020 *)

%o (Sage)

%o @CachedFunction

%o def T(n, k):

%o if (k<0 or k>n): return 0

%o elif (k==0): return fibonacci(n+1)

%o elif (n==1 and k==1): return 0

%o else: return T(n-1, k-1) + T(n-1, k) + T(n-2, k)

%o [T(2*n+3, n) for n in (0..30)] # _G. C. Greubel_, Jan 21 2020

%Y Cf. A055830.

%K nonn

%O 0,1

%A _Clark Kimberling_, May 28 2000