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A055828 a(n) = T(2n+4,n), array T as in A055818.

%I A055828 #11 Jan 23 2020 12:26:41
%S A055828 1,47,336,2128,12848,75808,441824,2557024,14737312,84726992,486388912,
%T A055828 2789840688,15995087184,91689974592,525608606912,3013422222272,
%U A055828 17280193763392,99117586397296,568696489153808,3263973649089808
%N A055828 a(n) = T(2n+4,n), array T as in A055818.
%H A055828 G. C. Greubel, <a href="/A055828/b055828.txt">Table of n, a(n) for n = 0..250</a>
%p A055828 T:= proc(i, j) option remember;
%p A055828       if i=0 or j=0 then 1
%p A055828     else add(add(T(h,m), m=0..j), h=0..i-1)
%p A055828   fi; end:
%p A055828 seq(T(n+4, n), n=0..30); # _G. C. Greubel_, Jan 22 2020
%t A055828 T[i_, j_]:= T[i, j]= If[i==0 || j==0, 1, Sum[T[h, m], {h,0,i-1}, {m,0,j}]]; Table[T[n+4, n], {n,0,25}] (* _G. C. Greubel_, Jan 22 2020 *)
%o A055828 (Sage)
%o A055828 @CachedFunction
%o A055828 def T(i, j):
%o A055828     if (i==0 or j==0): return 1
%o A055828     else: return sum(sum(T(h,m) for m in (0..j)) for h in (0..i-1))
%o A055828 [T(n+4, n) for n in (0..30)] # _G. C. Greubel_, Jan 22 2020
%Y A055828 Cf. A055818, A055819, A055820, A055821, A055822, A055823, A055824, A055825, A055826, A055827, A055829.
%K A055828 nonn
%O A055828 0,2
%A A055828 _Clark Kimberling_, May 28 2000