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 A367047 #10 Nov 03 2023 11:18:20
%S A367047 1,1,4,21,136,941,6864,52006,405312,3228654,26170764,215166638,
%T A367047 1789998808,15040070843,127450104568,1087988783356,9347556057040,
%U A367047 80766068931498,701359680126592,6117887649100980,53581405635501276,470988258063461393
%N A367047 G.f. satisfies A(x) = 1 - x^3 + x*A(x)^4.
%F A367047 a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(3*(n-3*k)+1,k) * binomial(4*(n-3*k),n-3*k)/(3*(n-3*k)+1).
%o A367047 (PARI) a(n) = sum(k=0, n\3, (-1)^k*binomial(3*(n-3*k)+1, k)*binomial(4*(n-3*k), n-3*k)/(3*(n-3*k)+1));
%Y A367047 Cf. A226022, A367046.
%Y A367047 Cf. A367043.
%K A367047 nonn
%O A367047 0,3
%A A367047 _Seiichi Manyama_, Nov 03 2023