"Flam" is usually used with two hands, but it's like having two hits very close to each other, not countable in sheet music. They do have a note for it that looks like a cue eigth note. But an example of a flan is hitting a snare with both your sticks, but not at the same time, to where it makes two seperate but rapid sounds. S in a sense it is kind of a "high speed roll," but not continuous.