What is the tracking calculation for the grouping of this 3-chain?

If the tracking calculation for this 3-chain is 8 x 3 + 1, what would the tracking calculation for a 20-chain?

If the tracking calculation for this 3-chain is 3 x 7 + 3 + 1, what would be the tracking calculation for an 100-chain?

Using the grouping of this 3-chain, what is the tracking calculation for an n-chain? Write you answer as an algebraic expression.

Key Stage 3

Dot chain sequences

What do we mean if we describe a sequence as "descending"?

Which of the following is an example of a descending sequence?

What is the nth term of 10, 8, 6, 4, 2, ...?

What is the nth term of -4, -7, -10, -13, ...?

Find the first 5 terms of the sequence -5n + 2.