Using rep to create an ID column

Question

I need to rep a sequence that has the following format:

1, 1, 2, 2, 3, 3,

4, 4, 4, 5, 5, 5, 6, 6, 6,

7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, etc.

I can do something similar to this with:

test<- as.data.frame(rep.int(1:9, rep(1:3, each = 3)))

But this starts with one observation for the first three numbers instead of two. The final product I'm looking for is something close to:

test2<- rep.int(1:10e3, rep(1:10, each = 1e3)) # this totals to 55,000 rows 
# in the correct format, but I am looking to get a total of 54,000 rows
# and I can't figure out the right combination of arguments. 

Any insight anyone has would be greatly appreciated.