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 A348322 #15 Oct 13 2021 10:25:28
%S A348322 1,1,-2,-48,1626,931040,-479909170,-5499596761127,43158334880135692,
%T A348322 9081843551946977373216,-1095541637114516172591381711,
%U A348322 -4049135740387789992460066844854898,7569951149407063102291625516677078697579
%N A348322 a(n) = Sum_{k=0..n} (-1)^k * binomial(n^2 - k,n*k).
%H A348322 Seiichi Manyama, <a href="/A348322/b348322.txt">Table of n, a(n) for n = 0..57</a>
%F A348322 a(n) = [x^(n^2)] (1-x)^(n-1)/((1-x)^n + x^(n+1)).
%t A348322 a[n_] := Sum[(-1)^k * Binomial[n^2 - k, n*k], {k, 0, n}]; Array[a, 13, 0] (* _Amiram Eldar_, Oct 12 2021 *)
%o A348322 (PARI) a(n) = sum(k=0, n, (-1)^k*binomial(n^2-k, n*k));
%o A348322 (PARI) a(n) = polcoef((1-x)^(n-1)/((1-x)^n+x^(n+1)+x*O(x^n^2)), n^2);
%Y A348322 Cf. A078001, A348315, A348321.
%K A348322 sign
%O A348322 0,3
%A A348322 _Seiichi Manyama_, Oct 12 2021