The numbers are counting down by 2 each step.

• 63 - 2 = 61, so the pattern decreases by 2.
• 61 - 2 = 59
• 59 - 2 = 57
• Check: 57 - 2 = 55, 55 - 2 = 53, 53 - 2 = 51. ✓

Final Answer: 59, 57