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 A381944 #10 Mar 11 2025 08:02:15
%S A381944 1,4,16,89,655,5592,51594,499159,4990821,51140527,534152690,
%T A381944 5665496618,60854697427,660601882734,7235771990454,79870211543625,
%U A381944 887569516968685,9921579561050637,111487286796322366,1258604967618419118,14268057344239960863,162358119295068686098
%N A381944 G.f. A(x) satisfies A(x) = B(x*A(x)) / (1 - x)^3, where B(x) is the g.f. of A001764.
%F A381944 a(n) = Sum_{k=0..n} binomial(4*k+1,k) * binomial(n+2*k+2,n-k)/(4*k+1).
%o A381944 (PARI) a(n) = sum(k=0, n, binomial(4*k+1, k)*binomial(n+2*k+2, n-k)/(4*k+1));
%Y A381944 Cf. A162481, A366034, A381947.
%Y A381944 Cf. A001764.
%K A381944 nonn
%O A381944 0,2
%A A381944 _Seiichi Manyama_, Mar 10 2025