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 A192670 #7 Feb 28 2017 00:32:26
%S A192670 1,1,1,2,4,7,11,19,33,56,94,160,271,461,785,1337,2279,3890,6644,11357,
%T A192670 19426,33246,56930,97535,167177,286665,491745,843842,1448530,2487302,
%U A192670 4272238,7340067,12614059,21682694,37279415,64108676,110268453,189700207,326408942,561733093,966869803
%N A192670 Floor-Sqrt transform of central trinomial coefficients (A002426).
%H A192670 G. C. Greubel, <a href="/A192670/b192670.txt">Table of n, a(n) for n = 0..1000</a>
%F A192670 a(n) = floor(sqrt(trinomial(2*n,n))).
%t A192670 FSFromSeries[f_,x_,n_] := Map[Floor[Sqrt[#]]&,CoefficientList[Series[f,{x,0,n}],x]]
%t A192670 FSFromSeries[1/Sqrt[1-2x-3x^2],x,100]
%K A192670 nonn
%O A192670 0,4
%A A192670 _Emanuele Munarini_, Jul 07 2011