Can `sample()` in R just sample in a specified order?

I was wondering how I could generate 1000 integers from 1 to 1000, one at a time in R. Making this a function, this means on the first run 1, on the second run 2, on the third run 3, ...?

I have tried the following in R with no success:

gen = function(n){
  sample(1:n, 1, replace = FALSE)
  }
gen(1000)