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 A369212 #5 Jan 16 2024 08:32:41
%S A369212 1,2,5,15,50,177,652,2473,9594,37892,151846,615859,2523217,10427471,
%T A369212 43415259,181941198,766841846,3248517320,13823977350,59067577266,
%U A369212 253315964424,1089998388418,4704475230340,20361365646315,88351705071583,384280788724692,1675063399090659
%N A369212 Expansion of (1/x) * Series_Reversion( x / ((1+x)^2+x^3) ).
%H A369212 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A369212 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} binomial(n+1,k) * binomial(2*n-2*k+2,n-3*k).
%o A369212 (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/((1+x)^2+x^3))/x)
%o A369212 (PARI) a(n) = sum(k=0, n\3, binomial(n+1, k)*binomial(2*n-2*k+2, n-3*k))/(n+1);
%Y A369212 Cf. A002212, A071356, A369158.
%Y A369212 Cf. A071879, A192132.
%K A369212 nonn
%O A369212 0,2
%A A369212 _Seiichi Manyama_, Jan 16 2024