_ _ _ a |_ b | c | d e | f | g |_ h i j/*End of Sequence*/ a |_ b | c | d |_ e | f g |_ h i | j/*End of Sequence*/
You find a piece of paper in the print tray with the above characters printed. You notice that the space between the h and the i is blank. What should be placed there and why?
Read the title again.
P.S. I've used both number-sequence and letter-sequence because I don't want to reveal what kind of a sequence it is. Will enigmatic-puzzles be valid here as well?