|
| |
|
|
A065498
|
|
Number of invertible n X n matrices mod 6 (i.e. over the ring Z_6).
|
|
1
| |
|
|
1, 2, 288, 1886976, 489104179200, 4755360379856486400, 1695944421638473850132889600, 21967113634648374162210646578639667200, 10286692771039109536373764545035369981946101760000
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
LINKS
| J. Overbey, W. Traves and J. Wojdylo, On the Keyspace of the Hill Cipher
|
|
|
FORMULA
| a(n) = 6^(n^2) * product k=1..n ((1 - 1/2^k)(1 - 1/3^k))
|
|
|
MATHEMATICA
| a[n_] := 6^(n^2)*Product[(1 - 1/2^k)*(1 - 1/3^k), { k, 1, n} ]; Table[ a[n], {n, 1, 9} ]
|
|
|
CROSSREFS
| Cf. A065128.
Sequence in context: A172374 A080296 A163276 * A203771 A057746 A132518
Adjacent sequences: A065495 A065496 A065497 * A065499 A065500 A065501
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Dan Fux (dan.fux(AT)OpenGaia.com or danfux(AT)OpenGaia.com), Nov 25 2001
|
|
|
EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 28 2001
|
| |
|
|
