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 A054114 #18 Apr 09 2020 09:35:16
%S A054114 1,8,28,98,350,1274,4706,17576,66196,250952,956384,3660540,14061140,
%T A054114 54177740,209295260,810375650,3143981870,12219117170,47564380970,
%U A054114 185410909790,723668784230,2827767747950,11061198475550,43308802158650,169719408596402,665637941544506
%N A054114 T(2n+1,n), array T as in A054110.
%C A054114 Apart from the initial term, identical to A066796(n+1).
%F A054114 G.f.: (-1+3*x+5*x^2-4*x^3+sqrt(1-4*x))/(x*(1-x)*(1-4*x)). - _Ralf Stephan_, Apr 03 2004; corrected by _Georg Fischer_, Apr 09 2020
%F A054114 For n>0, a(n) = sum(k=1, n+1, C(2k, k)). - _Ralf Stephan_, Apr 03 2004
%t A054114 CoefficientList[Series[(-1+3*x+5*x^2-4*x^3+Sqrt[1-4*x])/(x*(1-x)(1-4*x)), {x,0,30}],x] (* _Georg Fischer_, Apr 09 2020 *)
%Y A054114 Cf. A054110, A066796.
%K A054114 nonn
%O A054114 0,2
%A A054114 _Clark Kimberling_
%E A054114 Corrected by _Franklin T. Adams-Watters_, Oct 25 2006
%E A054114 a(23)-a(25) corrected by _Georg Fischer_, Apr 09 2020