

A001309


Order of real Clifford group L_n connected with BarnesWall lattices in dimension 2^n.


12




OFFSET

0,1


LINKS

Table of n, a(n) for n=0..8.
G. Nebe, E. M. Rains and N. J. A. Sloane, SelfDual Codes and Invariant Theory, Springer, Berlin, 2006.
A. R. Calderbank, E. M. Rains, P. W. Shor and N. J. A. Sloane, Quantum error correction via codes over GF(4), IEEE Trans. Inform. Theory, 44 (1998), 13691387.
G. Nebe, E. M. Rains and N. J. A. Sloane, The invariants of the Clifford groups, Des. Codes Crypt. 24 (2001), 99121.
Index entries for sequences related to BarnesWall lattices
Index entries for sequences related to groups


MAPLE

2^(n^2+n+2) * (2^n  1) * product('2^(2*i)1', 'i'=1..n1);


MATHEMATICA

a[0] = 2; a[n_] := 2^(n^2+n+2) * (2^n1) * Product[2^(2*i)1, {i, 1, n1}]; Table[a[n], {n, 0, 8}] (* JeanFrançois Alcover, Jul 16 2015, after Maple *)


CROSSREFS

2^(2n+2) times order of Chevalley group D_n (2) (cf. A001308). Twice A014115. See also A014116, A003956 (for the complex group).
Sequence in context: A060597 A091479 A016031 * A132569 A165644 A203315
Adjacent sequences: A001306 A001307 A001308 * A001310 A001311 A001312


KEYWORD

nonn,easy,nice


AUTHOR

N. J. A. Sloane, Peter Shor


STATUS

approved



