How to use values from array in FFMPEG expression?

I have a text file containing a list of 30 numeric values and I'm making a 1-second video at 30fps.

# values.txt
0 0.1 0.6 0.8 1.0 ... <= 30 values

How can I use those values per frame in, for instance, an eq filter?

Something like reading the array then using the current frame number to get a value from the array:

# pseudo FFMPEG code
values=$(cat values.txt)
arr=($values)
ffmpeg -i in.mp4 -filter-complex eq=brightness=${arr}[n]:eval=frame out.mp4

You would use elements of the form eq(N\,frame#)*value and add them together.

For three frames it would be

eq=brightness=eq(N\,0)*0+eq(N\,1)*0.1+eq(N\,2)*0.6:eval=frame