Using 
`cats :: Integer -> String`

How do I display 
`> cats 5`

Will show

```
cats
cats cats
cats cats cats
cats cats cats cats
cats cats cats cats cats

```

I've tried a single line and multi-line output

`cat n = concat["cat\n" | n <- [0..n-1]]`
and
`cat_row n = concat["cat " | m <- [0..n-1], m < n]`

but I'm not sure how to combine them.