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 A366355 #6 Feb 16 2025 08:34:06
%S A366355 1,0,3,416,722925,23205371904,17674407688984375,
%T A366355 384914699001548351078400,278893192683059452825059069034425,
%U A366355 7650586837724400321220283274999910891520000,8900101000088880011112998877890031110997889100010099891
%N A366355 a(n) = (-1)^n * QPochhammer(n, n, n).
%H A366355 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/q-PochhammerSymbol.html">q-Pochhammer Symbol</a>.
%F A366355 For n>0, a(n) = (1 - 1/n)^n * Product_{k=1..n} Sum_{j=1..k} n^j.
%F A366355 a(n) ~ n^(n*(n+1)/2).
%t A366355 Table[(-1)^n * QPochhammer[n, n, n], {n, 0, 12}]
%t A366355 Join[{1}, Table[Product[Sum[n^j, {j, 1, k}], {k, 1, n}] * (1 - 1/n)^n, {n, 1, 12}]]
%Y A366355 Cf. A023813.
%K A366355 nonn
%O A366355 0,3
%A A366355 _Vaclav Kotesovec_, Oct 08 2023