You can make arrays of numbers very easily. It is very much like making a variable. Let's say we want an array of 16 numbers:
16 array sixteen
That's it, we're done! You must omit the word 'CELLS', since 'ARRAY' implicates that you want an array of numbers, not characters. The size is a literal expression. You can't take it from the stack or calculate it, so this is invalid:
3 5 * 1+ array sixteen
4tH will let you know that this is not a valid construction, but in case you wonder..