its the Fibonacci sequence
The spacing is 6 1+6=7 7+6=13 13+6=19 19+6=25 so the missing number in the sequence is 13
Fibonacci sequence Fibonacci sequence
8 and 34 Alterative answer: Convensionally, the Fibonacci sequence starts with two 1s. So 1 and 8 are missing.
arithmetic
The pattern is plus 7. So the next number used to be 1.
The Fibonacci sequence starts with 0, 1. Each subsequent number is the sum of the two preceding ones. So the sequence goes: 0, 1, 1, 2, 3, 5, 8, 13, and so on.
The spacing is 6 1+6=7 7+6=13 13+6=19 19+6=25 so the missing number in the sequence is 13
Fibonacci Sequence
Fibonacci sequence Fibonacci sequence
8 and 34 Alterative answer: Convensionally, the Fibonacci sequence starts with two 1s. So 1 and 8 are missing.
arithmetic
The pattern is plus 7. So the next number used to be 1.
Usually a sequence is written using subscripts to represent a number in the sequence. Example: The sequence 1, 7, 13, 19, 25 is by adding six each time. So we can write it as: a_0 = 1 a_1 = 7 a_(n) = a_(n-1) + 6, where n is the subscript.
1, 1 are the first two numbers in the sequence; so, that's where you begin. In the Fibonacci sequence, you add numbers. Each sum is added to the previous largest number, to make the next number in the sequence. So, adding the first two numbers; 1 + 1 = 2. Then, as 2 was the resulting sum; and one was the last largest number, you add them. 1 + 2 = 3. And so on... The first ten numbers in the sequence are; 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. It continues like this, indefinitely.
121
13, 21 - it is the Fibonacci sequence
Start with the numbers 1 and 1. After that, every number in the sequence is the sum of the previous two numbers. Thus, the sequence starts with: 1, 1, 2, 3, 5, 8, 13, ...