Problem 312. Better bullseye matrix

Problem 18 asks to create a bullseye matrix like this:

[ 3 3 3 3 3
  3 2 2 2 3 
  3 2 1 2 3
  3 2 2 2 3 
  3 3 3 3 3 ] 

But I think a better one would look like this:

[ 5 4 3 4 5
  4 3 2 3 4
  3 2 1 2 3
  4 3 2 3 4
  5 4 3 4 5 ]

Thus given n (always odd), return output a that has concentric rings of the numbers 1 through n around the center point.