%I A003053 M1716
%S A003053 1,2,6,48,720,23040,1451520,185794560,47377612800,24257337753600,24815256521932800,
%T A003053 50821645356918374400,208114637736580743168000,1704875112338069448032256000,
%U A003053 27930968965434591767112450048000,915241991059360703024740763172864000
%N A003053 Order of orthogonal group O(n,GF(2)).
%D A003053 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A003053 F. J. MacWilliams, Orthogonal matrices over finite fields, Amer. Math. 
               Monthly, 76 (1969), 152-164.
%H A003053 T. D. Noe, <a href="b003053.txt">Table of n, a(n) for n=0..40</a>
%F A003053 For formulae see Maple code.
%p A003053 h:=proc(n) local m;
%p A003053 if n mod 2 = 0 then m:=n/2;
%p A003053 2^(m^2)*mul( 4^i-1, i=1..m);
%p A003053 else m:=(n+1)/2;
%p A003053 2^(m^2)*mul( 4^i-1, i=1..m-1);
%p A003053 fi;
%p A003053 end;
%Y A003053 Bisections give A003923 and A090770.
%Y A003053 Sequence in context: A052735 A052717 A129464 this_sequence A113296 A063744 
               A141609
%Y A003053 Adjacent sequences: A003050 A003051 A003052 this_sequence A003054 A003055 
               A003056
%K A003053 nonn,easy
%O A003053 0,2
%A A003053 N. J. A. Sloane (njas(AT)research.att.com). Edited by N. J. A. Sloane 
               (njas(AT)research.att.com), Dec 30 2008.