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 A357341 #6 Oct 01 2022 08:38:28
%S A357341 1,2,5,16,97,2186,57661,1018732,13546529,1146511702,102660872221,
%T A357341 2825817094376,-145181157396863,13773236811700354,5271279146947177757,
%U A357341 116514699193035121156,-76433013927946696971839,1553218338489700863557582,3403068210845899797768538429
%N A357341 a(n) = Sum_{k=0..n} (-1)^(n - k) * A357340(n, k).
%Y A357341 Cf. A357340.
%K A357341 sign
%O A357341 0,2
%A A357341 _Peter Luschny_, Sep 25 2022