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 A349471 #13 Nov 20 2021 08:00:53
%S A349471 1,0,5,71,1625,48699,1815157,80960200,4205895521,249447427145,
%T A349471 16631893722851,1231521399730489,100270564101729529,
%U A349471 8903719880410535595,856322102196977446955,88677383473792696758599,9837660365763014667911553,1163993530309417488368300653
%N A349471 a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(k*n,k).
%F A349471 a(n) ~ exp(n - 1/2) * n^(n - 1/2) / sqrt(2*Pi). - _Vaclav Kotesovec_, Nov 20 2021
%t A349471 a[n_] := Sum[(-1)^(n - k) * Binomial[k*n, k], {k, 0, n}]; Array[a, 20, 0] (* _Amiram Eldar_, Nov 19 2021 *)
%o A349471 (PARI) a(n) = sum(k=0, n, (-1)^(n-k)*binomial(k*n, k));
%Y A349471 Cf. A226391, A349470.
%K A349471 nonn
%O A349471 0,3
%A A349471 _Seiichi Manyama_, Nov 19 2021