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 A369027 #13 Jan 12 2024 15:26:10 %S A369027 0,0,2,18,216,3200,56250,1143072,26353376,679477248,19371024450, %T A369027 605000000000,20542440283992,753410487877632,29681760446040794, %U A369027 1250100767875276800,56050417968750000000,2665554518651030208512,134012922425586555796674 %N A369027 a(n) = floor(n^2 * (n - 1)^(n - 1) / 2). %t A369027 A369027[n_] := If[n == 1, 0, n^2 (n-1)^(n-1) / 2]; %t A369027 Array[A369027,30,0] (* _Paolo Xausa_, Jan 12 2024 *) %o A369027 (SageMath) %o A369027 def A369027(n): return ((n - 1)^(n - 1)*n^2)//2 %o A369027 print([A369027(n) for n in range(22)]) %Y A369027 Cf. A369025, A369026. %K A369027 nonn %O A369027 0,3 %A A369027 _Peter Luschny_, Jan 12 2024