You must have got an error message when executing - what did it say? That should be your first clue as to what's wrong with the code.
In your case, the multiplication sign is missing '*'.
A = magic(4)
B = [A 2*A; A.^2 A+2]
Output:
>> B
B =
16 2 3 13 32 4 6 26
5 11 10 8 10 22 20 16
9 7 6 12 18 14 12 24
4 14 15 1 8 28 30 2
256 4 9 169 18 4 5 15
25 121 100 64 7 13 12 10
81 49 36 144 11 9 8 14
16 196 225 1 6 16 17 3
