Bash from version 4 also has the mapfile
built-in command for reading lines into an array, and it has an option for setting the initial index value, so line one can be index one.
mapfile -t -O 1 array <file
Or if you want to do it the hard way, try something like this:
while read line ; do
(( x == 4 )) && echo "$line" && break
(( x++ ))