Question: Help with lfsrlength in Maple 9

Hi all 

I very very new to Maple so please forgive me if this not a great question.

I'm trying to input the command lfsrlength(v,n) to calculate the determinants mod 2, however Maple is just returning the command and not the determinants please see below

L101;  [1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1,
        1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0,
        1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1,
        0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1,
        1, 1, 0, 0, 0]

> lfsrlength([1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1], 15);

  lfsrlength([1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0,
        0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1], 15)
> 

If any one can please shed some light as to what I'm doing wrong it would be greatly appreciated.

Thanks