;Task:
Produce a spiral array.


A &nbsp; ''spiral array'' &nbsp; is a square arrangement of the first &nbsp; <big> N<sup>2</sup></big> &nbsp; natural numbers, &nbsp; where the
<br>numbers increase sequentially as you go around the edges of the array spiraling inwards.


For example, given &nbsp; '''5''', &nbsp; produce this array:
<pre>
 0  1  2  3  4
15 16 17 18  5
14 23 24 19  6
13 22 21 20  7
12 11 10  9  8
</pre>


;Related tasks:
* &nbsp; [[Zig-zag matrix]]
* &nbsp; [[Identity_matrix]]
* &nbsp; [[Ulam_spiral_(for_primes)]]
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