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 A343429 #25 Apr 16 2021 08:50:58
%S A343429 1,1,-4,52,-1252,47380,-2589892,193480948,-18967658404,2364328255444,
%T A343429 -365398042310020,68588722144816564,-15372942045464127076,
%U A343429 4055513943597589455508,-1243968998818298201100868,439009056263271003371155060,-176627099114433045240563153188,80365037678138695452520237597012,-41059325231828016124174743746157316
%N A343429 G.f.: 1 + 1^2*x/(1 + 2^2*x/(1 + 3^2*x/(1 + 4^2*x/(1 + 5^2*x/(1 + ...))))).
%H A343429 Seiichi Manyama, <a href="/A343429/b343429.txt">Table of n, a(n) for n = 0..242</a>
%F A343429 G.f.: 1/(Sum_{k>=0} A028296(k) * x^k).
%o A343429 (PARI) a(n) = my(A=1+O(x)); for(i=1, n, A=1+(n-i+1)^2*x/A); polcoef(A, n);
%Y A343429 Cf. A000364, A028296, A343427, A343428.
%K A343429 sign
%O A343429 0,3
%A A343429 _Seiichi Manyama_, Apr 15 2021