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 A369622 #10 Jan 28 2024 09:19:31
%S A369622 1,2,7,31,151,783,4243,23740,136099,795321,4719980,28370532,172357487,
%T A369622 1056658346,6528779587,40614467912,254167595939,1599012530917,
%U A369622 10107091256418,64155246033712,408780285886008,2613634555525584,16763436345211527,107827070566159112
%N A369622 Expansion of (1/x) * Series_Reversion( x / (1/(1-x)^2 + x^3) ).
%H A369622 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A369622 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} binomial(n+1,k) * binomial(3*n-5*k+1,n-3*k).
%o A369622 (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/(1/(1-x)^2+x^3))/x)
%o A369622 (PARI) a(n) = sum(k=0, n\3, binomial(n+1, k)*binomial(3*n-5*k+1, n-3*k))/(n+1);
%Y A369622 Cf. A369621, A369623.
%K A369622 nonn
%O A369622 0,2
%A A369622 _Seiichi Manyama_, Jan 27 2024