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 A092467 #21 Jul 02 2023 18:35:59
%S A092467 1,3,13,63,309,1511,7373,35951,175269,854455,4165565,20307647,
%T A092467 99002389,482649479,2352978861,11471077391,55922991237,272631840855,
%U A092467 1329115610269,6479611111519,31588945184245,154000207833639
%N A092467 a(n) = Sum_{i+j+k=n, 0<=i,j,k<=n} (n+2k)!/(i! * j! * (3*k)!).
%C A092467 In general, Sum_{k=0..n} C(n+2k,3k)*r^k has g.f. (1-r*x)^2/(1-(3r+1)*x+3r^2*x^2-r^3*x^3). - _Paul Barry_, Aug 23 2007
%H A092467 Seiichi Manyama, <a href="/A092467/b092467.txt">Table of n, a(n) for n = 0..200</a>
%H A092467 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (7, -12, 8).
%F A092467 G.f.: (1-4x+4x^2)/(1-7x+12x^2-8x^3). - _Ralf Stephan_, Dec 02 2004
%F A092467 a(n) = Sum_{k=0..n} C(n+2k,3k)*2^(n-k). - _Paul Barry_, Aug 23 2007
%Y A092467 Cf. A007583.
%K A092467 nonn
%O A092467 0,2
%A A092467 _Benoit Cloitre_, Mar 25 2004