Does this fit what you were looking for, or should we try a different genre for the sequence?
The monitor hummed, the only light in the cramped basement. On the screen, a single line of text blinked against the void: 00 X T M O S J B 00 X rar 00 X T M O S J B 00 X rar
Elias tapped his fingers against the desk. It was an impossible extension—a phantom file. "RAR" suggested a container, but the prefix was a sequence he hadn’t seen since the old mainframe days. X-T-M-O-S-J-B. Does this fit what you were looking for,