# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a369620
Showing 1-1 of 1

%I A369620 #9 Jan 28 2024 09:19:54
%S A369620 1,3,16,100,692,5099,39240,311700,2536490,21037102,177176745,
%T A369620 1511211409,13027296723,113319727772,993422328313,8768003882546,
%U A369620 77848008692270,694828468698510,6230785015298952,56109079416527835,507188912618646021,4600432953729579585
%N A369620 Expansion of (1/x) * Series_Reversion( x / (1/(1-x)^3 + x^2) ).
%H A369620 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A369620 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/2)} binomial(n+1,k) * binomial(4*n-5*k+2,n-2*k).
%o A369620 (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/(1/(1-x)^3+x^2))/x)
%o A369620 (PARI) a(n) = sum(k=0, n\2, binomial(n+1, k)*binomial(4*n-5*k+2, n-2*k))/(n+1);
%Y A369620 Cf. A369618, A369619.
%K A369620 nonn
%O A369620 0,2
%A A369620 _Seiichi Manyama_, Jan 27 2024

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE