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 A367462 #13 Jan 27 2024 10:31:47
%S A367462 1,1,1,2,4,7,14,30,62,131,287,629,1385,3096,6967,15735,35782,81823,
%T A367462 187781,432689,1000919,2322584,5405094,12614260,29512587,69205602,
%U A367462 162634994,382961435,903431963,2134945637,5053385429,11979405642,28438444486,67601886687
%N A367462 Expansion of (1/x) * Series_Reversion( x / (1+x+x^3/(1+x)) ).
%H A367462 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A367462 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} binomial(n+1,k) * binomial(n-2*k+1,n-3*k).
%o A367462 (PARI) my(N=40, x='x+O('x^N)); Vec(serreverse(x/(1+x+x^3/(1+x)))/x)
%o A367462 (PARI) a(n) = sum(k=0, n\3, binomial(n+1, k)*binomial(n-2*k+1, n-3*k))/(n+1);
%Y A367462 Cf. A126042.
%K A367462 nonn
%O A367462 0,4
%A A367462 _Seiichi Manyama_, Jan 26 2024