> df <- data.frame(g = c(1, 1, 2, 2), n = 1:4)
> df %>% count(g, wt = n)
  g n
1 1 3
2 2 7

> df %>% count(g, wt = n) %>% count(wt = n)
   n
1 10

> df %>% count(n)
Message: Storing counts in `nn`, as `n` already present in input
i Use `name = "new_name"` to pick a new name.

  n nn
1 1  1
2 2  1
3 3  1
4 4  1

