fill 3 ; fill 2 '* ' ; echo
fill 2 ; fill 4 '* ' ; echo
fill 1 ; fill 6 '* ' ; echo
fill 0 ; fill 8 '* ' ; echo
fill 1 ; fill 6 '* ' ; echo
fill 2 ; fill 4 '* ' ; echo
fill 3 ; fill 2 '* ' ; echo

#!/bin/dash

fill ()
{
    # fill string to width of count from string chars 
    #
    # usage:
    #      fill count [chars]
    #
    # if count is zero (or less) a blank string is output
    # chars defaults to a space
    #
    local width=$(( ($1) ))
    local str="${2:- }"

    while [ $width -gt 0 ]
    do
        while [ ${#str} -gt $width ]
        do
            str=${str%?}
        done
        width=$((width-${#str}))
        printf "%s" "$str"
    done
}

printf "Enter the mininum number: "
read MIN
printf "Enter the maximum number: "
read MAX

STARS=0
N=$MIN
while [ $N -le $((MAX*2-MIN)) ]
do
    A=$((N-MAX))
    W=$(($MAX-${A#-}))
    fill MAX-W ; fill W*2 '* ' ; echo
    STARS=$((STARS+W))
    N=$((N+1))
done
echo "Total stars: $STARS"