We easily see the pattern of the odd-numbered terms,
start with 64 and take half each time:

 64, __, 32, __, 16, __,  8, __,  4, __,  2, __

Then we notice that the term on the left of 32 is 3
more than 32, and the term on the right of 32 is 3 less
than 32,

 64, 35, 32, 29, 16, __,  8, __,  4, __,  2, __

So the one just before 8 is 3 more than 8, or 11, and the
term on the right of 8 is 3 less than 8, or 5.  And the 
pattern goes like this:

 64, 35, 32, 29, 16, 11,  8,  5,  4,  5,  2, -1

Edwin