%I #6 Oct 04 2012 10:28:50
%S 12,2592,50388480,80225312993280,10358730921842550374400,
%T 108354149159204252828272715366400,
%U 91807063616969429053277006948134413139968000,6300752103463414524173850924959140409591369032708128768000,35026261744325078751960598643637064012678383486922588643915999981076480000
%N 4*3^(n^2+2n+1)*Product_{j=1..n} (9^j-1).
%C The order of the p-Clifford group for an odd prime p is a*p^(n^2+2n+1)*Product_{j=1..n} (p^(2*j)-1), where a = gcd(p+1,4).
%H G. Nebe, E. M. Rains and N. J. A. Sloane, <a href="http://neilsloane.com/doc/cliff2.html">Self-Dual Codes and Invariant Theory</a>, Springer, Berlin, 2006.
%Y Cf. A001309, A003956.
%Y Cf. A092299 and A092301 (p=3), A092300 and A089989 (p=5), A090768 and A090769 (p=7), A090770 (p=2, although this is the wrong formula in that case).
%K nonn
%O 0,1
%A _N. J. A. Sloane_, Feb 10 2004