RegEx for number pattern patching

[CorvusPrime]

I am looking for a preg_match expression that will find recurring patterns in a space delimited list of 1-2 digit numbers.

New to regex and trying to get my head around this so I can do it lucidly in the future.

[CorvusPrime]

BTW: I have tried the following:

/[0-9]{1,2} [0-9]{1,2} [0-9]{1,2}/\1+

And what I get is an error about unknown modifier in reference to the final \1+