1. Startling
2. Starring (remove "L")
3. Staring (remove "R")
4. String (remove "A")
5. Sting (remove "R")
6. Sing (remove "T")
7. Sings (remove "N")
8. Sigh (remove "S")
9. Ship (remove "G")
10. Shop (remove "I")
11. Chop (remove "S")
12. Chap (remove "O")
13. Chat (remove "P")
14. That (remove "C")
15. Than (remove "T")
16. Than (remove "H")
17. Thaw (remove "N")
18. What (remove "A")
What is the sequence? This is the final word, so the sequence is the list of words we created by removing one letter at a time!