OFFSET
0,1
COMMENTS
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). This is the sequence obtained by (illegally) setting p = 2.
LINKS
G. Nebe, E. M. Rains and N. J. A. Sloane, Self-Dual Codes and Invariant Theory, Springer, Berlin, 2006.
MATHEMATICA
Table[2^(n^2+2n+1) Product[4^j-1, {j, n}], {n, 0, 10}] (* Harvey P. Dale, May 14 2022 *)
PROG
(Python)
from math import prod
def A090770(n): return prod((1<<i)-1 for i in range(2, 2*n+1, 2)) << (n+1)**2 # Chai Wah Wu, Jun 20 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 10 2004
STATUS
approved