%I #10 Jun 14 2024 22:31:08
%S 1,36,20160,174182400,23499295948800,50027557148216524800,
%T 1691555775522928280469504000,911666827031785075278550369566720000,
%U 7846393898179181843651374899795632943267840000
%N Order of Chevalley group D_n (2).
%D J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, ATLAS of Finite Groups. Oxford Univ. Press, 1985 [for best online version see https://oeis.org/wiki/Welcome#Links_to_Other_Sites], p. xvi.
%D H. S. M. Coxeter and W. O. J. Moser, Generators and Relations for Discrete Groups, 4th ed., Springer-Verlag, NY, reprinted 1984, p. 131.
%H T. D. Noe, <a href="/A001308/b001308.txt">Table of n, a(n) for n = 1..20</a>
%F a(n) = 2^(n*(n-1)) * (2^n - 1) * Product_{i=1..n-1} (2^(2*i) - 1).
%p for m from 0 to 25 do N:=2^(m*(m-1))*mul( 4^i-1, i=1..m-1)*(2^m-1); lprint(N); od:
%Y Cf. A003923.
%K nonn,easy
%O 1,2
%A _N. J. A. Sloane_