Two Step Rules

You'll learnto tell an adding sequence from a multiplying one, and to jump straight to any term without counting your way there.

Two sequences start at the same number. One adds 4 every step; the other doubles. For a moment they look like cousins, and then one of them leaves the chart. This story follows that split from the first two terms to the savings account where it costs real money, and it stops on the counting slip that loses more points than either rule. Twelve short steps; press Next for each one.

12 STEPS · 6 QUICK CHECKS · a_n = a₀ + dn · g_n = g₀ · rⁿ · v3

one adds the same amount · one multiplies by the same factor

Before you start

What you're looking at

Two sequences that begin at the same number, one adding a fixed amount each step and one multiplying by a fixed factor.

The question

Which rule built this list, and how far ahead is the term you want?

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