Some Interesting Numbers: Happy 5-1-5-1-5

I know there is a name for this sort of a number or letter arrangement, but I can't remember it.

But ever since the May 11th, we have been having them.

5-1-1-1-5
5-1-2-1-5
5-1-3-1-5
5-1-4-1-5
5-1-5-1-5
5-1-6-1-5
5-1-7-1-5
5-1-8-1-5
5-1-9-1-5

Whoa. Them Numbers.  --RoadDog