Number series – multiply by 5, then alternate “+4, −4”: 6, 26, 134, 666, 3334, 16666, ? Apply the established ×5 and alternating addition/subtraction of 4 to find the next term.

Introduction / Context:
This pattern weaves a strong multiplicative jump (×5) with a tiny alternating adjuster (+4, −4). Such alternations are common distractors that you can verify quickly by checking sign flips at each step.

Given Data / Assumptions:

• 6 → 26 (= 6*5 − 4)
• 26 → 134 (= 26*5 + 4)
• 134 → 666 (= 134*5 − 4)
• 666 → 3334 (= 666*5 + 4)
• 3334 → 16666 (= 3334*5 − 4)

Concept / Approach:
Continue with ×5 then flip the sign again (now +4).

Step-by-Step Solution:

Verification / Alternative check:
Every step obeys ×5 with alternating ±4, so the extension is unambiguous.

Why Other Options Are Wrong:

Common Pitfalls:
Missing the small ±4 tweak and assuming pure ×5, which would be off by 4 each time.

Final Answer:
83334