Hope my question makes sense.
For instance just triggering track 1 on the 1 once, then have the trig somehow disappear by the next round of the pattern leaving the sound run endlessly to be manipulated by trigless keys.
I know I can do it manually in any number of ways, but wondering if I can program it so it happens entirely within the same pattern without any input control.
Maybe with an octatrack although I couldn’t begin to tell you how. If you have a digitakt it’s unlikely, as I don’t believe that there’s any way to subvert the nature of the sequencer.
You probably want to specify which model you’re asking about for more specific answers.
Thanks, right! Either the Syntakt, Digitakt or Digitakt II 
Syntakt doesn’t use samples so hard no on that one, not sure about digitakt II so I don’t want to make any assumptions. Good luck though, I hope you find what you need.
On the OT you can loop the sample (second page), and ad a 1st trig condition to the first step of the pattern. Don’t own a digitakt so not sure if this works there too.
Right on the Syntakt, that’s why I wrote sample/track And thanks, I hope i figure something out!
Wish for Firmware update: A count-down feature for trigs (that would work together with probability) so patterns could self-erase.
1ST trig condition
So now we know you are using digitakt.
Loop the sample and pick 1st trig condition.
Hey, THANKS everybody!