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A090769
a(n) = 7^(n^2+2n+1)*Product_{j=1..n} (49^j-1).
7
7, 115248, 4648735526400, 450407556363158605209600, 104778523164913973815626804401602560000, 58523610551335889301209607995669952696063684472995840000, 78484177614161178233131678359243733693084949841898468389173730723495936000000, 252711655239728880943018718373465881336679551349902568778399448766444479481704737212965012373504000000
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).
LINKS
G. Nebe, E. M. Rains and N. J. A. Sloane, Self-Dual Codes and Invariant Theory, Springer, Berlin, 2006.
MATHEMATICA
Table[7^(n^2 + 2 n + 1)*Product[49^j - 1, {j, n}], {n, 0, 7}] (* Wesley Ivan Hurt, Oct 15 2023 *)
CROSSREFS
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).
Sequence in context: A173839 A122000 A291906 * A013842 A247791 A243859
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 10 2004
STATUS
approved