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 A307094 #16 May 20 2021 04:44:26
%S A307094 1,0,-2,117,-9634,12625,6612982405,-59596651685928,718060704631041758,
%T A307094 93531932148176228605941,-94958916373783601251815537977,
%U A307094 135510731474135489426391897083350463
%N A307094 a(n) = Sum_{k=0..n} (-1)^k * binomial(n^2,k^2).
%H A307094 Seiichi Manyama, <a href="/A307094/b307094.txt">Table of n, a(n) for n = 0..57</a>
%F A307094 a(n) = A307093(n^2).
%t A307094 a[n_] := Sum[(-1)^k * Binomial[n^2, k^2], {k, 0, n}]; Array[a, 12, 0] (* _Amiram Eldar_, May 20 2021 *)
%o A307094 (PARI) {a(n) = sum(k=0, n, (-1)^k*binomial(n^2, k^2))}
%Y A307094 Cf. A000290, A206849, A307093.
%K A307094 sign
%O A307094 0,3
%A A307094 _Seiichi Manyama_, Mar 24 2019