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A027032 a(n) = T(n,2n-8), T given by A027023.

%I A027032 #9 Nov 05 2019 07:23:38
%S A027032 1,1,5,17,57,193,649,2161,7113,23137,74417,236913,747401,2339137,
%T A027032 7270189,22460801,69031105,211206529,643684485,1955082321,5920720729,
%U A027032 17884040961,53898818389,162120056257,486791503521,1459448379329
%N A027032 a(n) = T(n,2n-8), T given by A027023.
%H A027032 G. C. Greubel, <a href="/A027032/b027032.txt">Table of n, a(n) for n = 4..750</a>
%p A027032 T:= proc(n, k) option remember;
%p A027032       if k<3 or k=2*n then 1
%p A027032     else add(T(n-1, k-j), j=1..3)
%p A027032       fi
%p A027032     end:
%p A027032 seq(T(n,2*n-8), n=4..30); # _G. C. Greubel_, Nov 05 2019
%t A027032 T[n_, k_]:= T[n, k]= If[n<0, 0, If[k<3 || k==2*n, 1, Sum[T[n-1, k-j], {j, 3}]]]; Table[T[n, 2*n-8], {n,4,30}] (* _G. C. Greubel_, Nov 05 2019 *)
%o A027032 (Sage)
%o A027032 @CachedFunction
%o A027032 def T(n, k):
%o A027032     if (k<3 or k==2*n): return 1
%o A027032     else: return sum(T(n-1, k-j) for j in (1..3))
%o A027032 [T(n, 2*n-8) for n in (4..30)] # _G. C. Greubel_, Nov 05 2019
%K A027032 nonn
%O A027032 4,3
%A A027032 _Clark Kimberling_