Question

What is the pattern rule 1,4,13,40,121

Answer 1

the next number is 3 times of previous number + 1

Explanation:

like;

`4 = (1) * 3 + 1`

`13 = (4) * 3 + 1`

etc...

Answer 2

(x * 3) + 1

Explanation:

(1 * 3) + 1 = 4

(4 * 3) + 1 = 13

(13 * 3) + 1 = 40

etc