This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A055838 #12 Jan 21 2020 10:08:38 %S A055838 5,30,162,850,4425,22995,119560,622512,3246750,16963375,88779900, %T A055838 465386220,2443204946,12844119225,67608235800,356288599640, %U A055838 1879625199825,9925931817045,52464942758250,277546278287250 %N A055838 T(2n+4,n), where T is the array in A055830. %H A055838 G. C. Greubel, <a href="/A055838/b055838.txt">Table of n, a(n) for n = 0..500</a> %F A055838 Conjecture: 5*n*(n+3)*(n-1)*a(n) -2*(n-1)*(11*n+8)*(n+2)*a(n-1) -3*(3*n-1)*(3*n-2)*(n+1)*a(n-2)=0. - _R. J. Mathar_, Mar 13 2016 %p A055838 with(combinat); %p A055838 T:= proc(n, k) option remember; %p A055838 if k<0 or k>n then 0 %p A055838 elif k=0 then fibonacci(n+1) %p A055838 elif n=1 and k=1 then 0 %p A055838 else T(n-1, k-1) + T(n-1, k) + T(n-2, k) %p A055838 fi; end: %p A055838 seq(T(2*n+4, n), n=0..30); # _G. C. Greubel_, Jan 21 2020 %t A055838 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+4, n], {n,0,30}] (* _G. C. Greubel_, Jan 21 2020 *) %o A055838 (Sage) %o A055838 @CachedFunction %o A055838 def T(n, k): %o A055838 if (k<0 and k>n): return 0 %o A055838 elif (k==0): return fibonacci(n+1) %o A055838 elif (n==1 and k==1): return 0 %o A055838 else: return T(n-1, k-1) + T(n-1, k) + T(n-2, k) %o A055838 [T(2*n+4, n) for n in (0..30)] # _G. C. Greubel_, Jan 21 2020 %Y A055838 Cf. A055830. %K A055838 nonn %O A055838 0,1 %A A055838 _Clark Kimberling_, May 28 2000