User:Jacobzheng

A 14x2 halt TM:

0 _ 1 r 1
0 1 1 r 13
1 _ 1 r 2
1 1 _ l 6
2 _ 1 l 3
2 1 1 r 1
3 _ 1 l 5
3 1 1 l 4
4 _ 1 l 7
4 1 1 l 5
5 _ 1 r 6
5 1 _ l 3
6 _ 1 l 1
6 1 _ r 5
7 _ 1 r 8
7 1 1 r 7
8 _ 1 r halt
8 1 _ r 9
9 _ 1 r 8
9 1 1 l 10
10 _ _ l 10
10 1 1 l 11
11 _ 1 l 12
11 1 1 r 13
12 _ 1 r 7
12 1 _ l 11
13 _ _ r 0
13 1 1 l 10

It halts at step $>Ack(10\uparrow \uparrow 5)$