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 A290443 #10 Aug 05 2017 12:48:28
%S A290443 1,2,10,56,378,2772,21879,181610,1570426,14024660,128623768,
%T A290443 1206053576,11523121900,111885197400,1101664016730,10981102287240,
%U A290443 110647549986930,1125688857747300,11551507304378580,119462291733779280,1244159075360113380,13040616137944154760,137485676447508793950
%N A290443 a(n) = Catalan(n)*Motzkin(n-1).
%F A290443 Conjecture: n*(n+1)^2*a(n) -2*-n*(2*n-1)^2*a(n-1) -12*(n-2)*(2*n-1)*(2*n-3)*a(n-2)=0. - _R. J. Mathar_, Aug 05 2017
%t A290443 motzkin[n_]:=Hypergeometric2F1[(1-n)/2, -n/2, 2, 4]; Table[CatalanNumber[n] motzkin[n - 1], {n, 50}] (* _Indranil Ghosh_, Aug 04 2017 *)
%Y A290443 Cf. A000108, A001006, A151341, A290443.
%K A290443 nonn
%O A290443 1,2
%A A290443 _N. J. A. Sloane_, Aug 04 2017