Visual forward digit span, test 7. While the numbers are flashing, the cursor changes to a text cursor, but once they're gone, the cursor changes to the hand icon you get when you hover over a link.
The textbox is supposed to get focus once the digits stop flashing and the "enter your answer" prompt appears; if not, if you click the box at the point, input should work. You can contact me at fun at cognitivefun dot net if there are further problems.