Answer: What Comes Next? #446

The answer is B: 22.

The finished pattern: 1, 2, 4, 7, 11, 16, 22.
The finished pattern.

The rule

Add 1, then add 2, then add 3, then 4… The gap grows by one every time.

The pattern as Python code

Here is a tiny Python program that follows the same rule. Type it into IDLE and run it to print the whole pattern, including the answer.

number = 1
gap = 1
for step in range(7):
    print(number)
    number = number + gap
    gap = gap + 1

When you run it, Python prints:

1
2
4
7
11
16
22

Pixel says: Try changing a number in the code and run it again. Can you make the pattern go on for 20 steps? Meow!