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A027034 a(n) = T(n,2n-10), T given by A027023.

%I A027034 #7 Nov 05 2019 12:24:53
%S A027034 1,1,5,17,57,193,653,2205,7417,24805,82373,271437,887377,2878509,
%T A027034 9268429,29636981,94163769,297435285,934521973,2922073641,9096981049,
%U A027034 28209178729,87163760797,268462020889,824451264113,2525238433145
%N A027034 a(n) = T(n,2n-10), T given by A027023.
%H A027034 G. C. Greubel, <a href="/A027034/b027034.txt">Table of n, a(n) for n = 5..750</a>
%p A027034 T:= proc(n, k) option remember;
%p A027034       if k<3 or k=2*n then 1
%p A027034     else add(T(n-1, k-j), j=1..3)
%p A027034       fi
%p A027034     end:
%p A027034 seq(T(n,2*n-10), n=5..30); # _G. C. Greubel_, Nov 05 2019
%t A027034 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-10], {n,5,30}] (* _G. C. Greubel_, Nov 05 2019 *)
%o A027034 (Sage)
%o A027034 @CachedFunction
%o A027034 def T(n, k):
%o A027034     if (k<3 or k==2*n): return 1
%o A027034     else: return sum(T(n-1, k-j) for j in (1..3))
%o A027034 [T(n, 2*n-10) for n in (5..30)] # _G. C. Greubel_, Nov 05 2019
%K A027034 nonn
%O A027034 5,3
%A A027034 _Clark Kimberling_