Related Clues:

• 1,2,3, etc.
• Numbers
• 5 and 10, e.g.
• Mathematical figures
• See 6 Down
• 1, 2, 3, etc.
• Roman ___
• Roman __: thinly disguised fiction
• Arabic characters
• Roman ___ (novel type)
• See 15 Across
• Roman ___ (thinly disguised fiction)
• Symbols for numbers
• Roman ___ (novel genre)
• Ran mules out one-by-one