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 A381943 #12 Mar 11 2025 08:01:11
%S A381943 1,3,11,60,425,3426,29619,267738,2497889,23866056,232325475,
%T A381943 2295889266,22971682893,232248775669,2368969672183,24348849065860,
%U A381943 251930963865061,2621914660411919,27428338267887815,288258167672381602,3042002859317810001,32222429872821051817
%N A381943 G.f. A(x) satisfies A(x) = B(x*A(x)) / (1 - x)^2, where B(x) is the g.f. of A001764.
%F A381943 a(n) = Sum_{k=0..n} binomial(4*k+1,k) * binomial(n+k+1,n-k)/(4*k+1).
%o A381943 (PARI) a(n) = sum(k=0, n, binomial(4*k+1, k)*binomial(n+k+1, n-k)/(4*k+1));
%Y A381943 Partial sums of A364592.
%Y A381943 Cf. A086616, A381867, A381945.
%Y A381943 Cf. A001764.
%K A381943 nonn
%O A381943 0,2
%A A381943 _Seiichi Manyama_, Mar 10 2025