Hi guys, I have a very straightforward question:

My goal is to create a vector where the next value is equal to last value + a constant (call this `add1`

). However, when we get to a certain length (call this `threshold`

) we change the constant added to another one (call this `add2`

). The vector starts at 1. Thus, for example:

Let: `add1 = 1`

, `threshold = 5`

, `add2 = 4`

. We would have:

```
x
1 # start at 1
2 # since add1 = 1, add 1 to last value
3 # since add1 = 1, add 1 to last value
4 # since add1 = 1, add 1 to last value
8 # since threshold = 5, and this is the 5th position, add `add2 = 4` to last value
9
10
11
12
16 # since this is the 10th position (a multiple of `threshold`), add 4 to last value.
```

So far, I've tried this, but it doesn't work:

```
x <- c()
x[1] <- 1
for (i in seq_along(1:30)) {
if (i %% threshold == 0) {
x[i+1] <- x[i] + add2
}
x[i+1] <- x[i] + add1
}
```

I'd love to do this with a `map_*`

function, but I can't even do it with a `for`

loop... let alone doing it with `purrr`