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 A372920 #15 Jan 22 2025 17:01:37
%S A372920 1,1,6,123,7108,1058885,386056326,332908216711,662759754883080,
%T A372920 2991536714452469769,30189087071961437767690,
%U A372920 673536638307789642838763531,32919693104791033024939149066252,3498056629389633452501822564131061773,802931613320922331646386276441560583143438
%N A372920 Total number of n-colorings of all graphs on n labeled nodes.
%H A372920 Alois P. Heinz, <a href="/A372920/b372920.txt">Table of n, a(n) for n = 0..76</a>
%F A372920 a(n) = A322280(n,n).
%F A372920 a(n) == n (mod 2) for n >= 1.
%t A372920 nmax = 76;
%t A372920 a[n_] := 2^(n(n-1)/2)*n!*SeriesCoefficient[Sum[x^i/(2^(i(i-1)/2)*i!), {i, 0, nmax}]^n, {x, 0, n}];
%t A372920 Table[a[n],{n,0,nmax}] (* _Jean-François Alcover_, May 28 2024 *)
%Y A372920 Main diagonal of A322280.
%Y A372920 Cf. A000035, A006125.
%K A372920 nonn
%O A372920 0,3
%A A372920 _Alois P. Heinz_, May 16 2024