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A026785 a(n) = T(2n-1, n-2), T given by A026780.

%I A026785 #7 Nov 02 2019 20:00:19
%S A026785 1,9,60,361,2076,11672,64842,357897,1968788,10813804,59372770,
%T A026785 326086492,1792293014,9861375614,54324086446,299651439321,
%U A026785 1655124211372,9154654655044,50704627346170,281214708137032,1561706813618886
%N A026785 a(n) = T(2n-1, n-2), T given by A026780.
%H A026785 G. C. Greubel, <a href="/A026785/b026785.txt">Table of n, a(n) for n = 2..500</a>
%p A026785 T:= proc(n,k) option remember;
%p A026785     if n<0 then 0;
%p A026785     elif k=0 or k =n then 1;
%p A026785     elif k <= n/2 then
%p A026785         procname(n-1,k-1)+procname(n-2,k-1)+procname(n-1,k) ;
%p A026785     else
%p A026785         procname(n-1,k-1)+procname(n-1,k) ;
%p A026785     fi ;
%p A026785 end proc:
%p A026785 seq(T(2*n-1,n-2), n=2..30); # _G. C. Greubel_, Nov 02 2019
%t A026785 T[n_, k_]:= T[n, k]= If[n<0, 0, If[k==0 || k==n, 1, If[k<=n/2, T[n-1, k-1] + T[n-2, k-1] + T[n-1, k], T[n-1, k-1] + T[n-1, k] ]]];
%t A026785 Table[T[2*n-1, n-2], {n,2,30}] (* _G. C. Greubel_, Nov 02 2019 *)
%o A026785 (Sage)
%o A026785 @CachedFunction
%o A026785 def T(n, k):
%o A026785     if (n<0): return 0
%o A026785     elif (k==0 or k==n): return 1
%o A026785     elif (k<=n/2): return T(n-1,k-1) + T(n-2,k-1) + T(n-1,k)
%o A026785     else: return T(n-1,k-1) + T(n-1,k)
%o A026785 [T(2*n-1, n-2) for n in (2..30)] # _G. C. Greubel_, Nov 02 2019
%Y A026785 Cf. A026780, A026781, A026782, A026783, A026784, A026786, A026787, A026788, A026789, A026790.
%K A026785 nonn
%O A026785 2,2
%A A026785 _Clark Kimberling_