1 is 3, 2 is 3, 3 is 4, 4 is 4 and 5 is 4.

How can this possible?(explain the
rule)

x is 3 if x < 3

x is 4 is x >= 3

Given so few points, it is possible to posit any number of rules.

great! thank you Steve.

To understand how this sequence is possible, let's break it down and establish the rule governing the sequence.

In this sequence, each number is assigned a value that corresponds to the number of letters in its spelling. Let's analyze each number:

1: "one" has three letters, so 1 is assigned a value of 3.
2: "two" also has three letters, so 2 is assigned a value of 3.
3: "three" has five letters, so 3 is assigned a value of 4.
4: "four" also has four letters, so 4 is assigned a value of 4.
5: "five" has four letters, so 5 is assigned a value of 4.

As we can see, the assigned value for each number is based on the number of letters used to spell its corresponding word. This pattern continues similarly for other numbers in the sequence.

So, based on this rule, the sequence becomes:
1, 2, 3, 4, 5
3, 3, 4, 4, 4

Hence, the sequence 1 is 3, 2 is 3, 3 is 4, 4 is 4, and 5 is 4 is possible because each number is assigned a value based on the number of letters in its spelling.