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 A372017 #7 Apr 16 2024 10:26:31
%S A372017 1,3,-6,39,-213,1425,-9681,69393,-509307,3827856,-29254443,226787682,
%T A372017 -1778491446,14084085711,-112462798281,904485811944,-7319902809228,
%U A372017 59565238152789,-487071807495099,4000169922457260,-32980470088198209,272875134913543488
%N A372017 G.f. A(x) satisfies A(x) = ( 1 + 9*x/(1 - x*A(x)) )^(1/3).
%F A372017 a(n) = Sum_{k=0..n} 9^k * binomial(n/3-k/3+1/3,k) * binomial(n-1,n-k)/(n-k+1).
%o A372017 (PARI) a(n) = sum(k=0, n, 9^k*binomial(n/3-k/3+1/3, k)*binomial(n-1, n-k)/(n-k+1));
%Y A372017 Cf. A372003.
%K A372017 sign
%O A372017 0,2
%A A372017 _Seiichi Manyama_, Apr 15 2024