REAPER
Patch: http://www.elanhickler.com/misc/sine-sequence.FXP (hold down a note till the sequence repeats and turn CLK on)
(Step sequencer zoomed ALL the way in)
As you can see, even though i did my best to get rid of that straight line in the step sequencer, it's still there. This causes double clicks when the click option is enabled... i think.