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 A366083 #13 Sep 29 2023 09:27:53
%S A366083 1,3,14,78,478,3109,21063,146997,1049302,7624330,56198481,419155136,
%T A366083 3157356819,23984387314,183519131353,1413099475142,10941294442694,
%U A366083 85132006090350,665294548097852,5219591907202092,41095469624286421,324595783790966343
%N A366083 Expansion of (1/x) * Series_Reversion( x*(1-x)^4/(1-x-x^2) ).
%H A366083 Seiichi Manyama, <a href="/A366083/b366083.txt">Table of n, a(n) for n = 0..1000</a>
%F A366083 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/2)} (-1)^k * binomial(n+1,k) * binomial(4*n-k+2,n-2*k).
%o A366083 (PARI) a(n) = sum(k=0, n\2, (-1)^k*binomial(n+1, k)*binomial(4*n-k+2, n-2*k))/(n+1);
%Y A366083 Cf. A007440, A108623, A366081, A366082.
%Y A366083 Cf. A366050.
%K A366083 nonn
%O A366083 0,2
%A A366083 _Seiichi Manyama_, Sep 28 2023