1,2,5,26 calculate the missing number?
Answers
Answered by
2
1²+1=2
2²+1=5
5²+1=26
26²+1=677
Answered by
1
Try to find connections between the numbers.
2 - 1 = 1
5 - 2 = 3
12 - 5 = 7
29 - 12 = 17
Is the difference seems to be every two prime numbers? 1, 2, 3, 5, 7, 11, 13, 17 - no
1 + 2*2 = 5
2 + 5*2 = 12
5 + 12*2 = 29
The formula is, with x being the place in the sequence and y or f(x) being the output:
f(1) = 1, else f(x) = f(x - 2) + 2f(x-1)
Assume all numbers in the sequence before 1 are 0.
Therefore, we can substitute x with 6, because we are looking for the sixth number in the sequence.
f(6) = f(4) + 2f(5)
Since we know f(4) was 12 and f(5) was 29, we substitute those.
f(6) = 12 + 58
f(6) = 70
2 - 1 = 1
5 - 2 = 3
12 - 5 = 7
29 - 12 = 17
Is the difference seems to be every two prime numbers? 1, 2, 3, 5, 7, 11, 13, 17 - no
1 + 2*2 = 5
2 + 5*2 = 12
5 + 12*2 = 29
The formula is, with x being the place in the sequence and y or f(x) being the output:
f(1) = 1, else f(x) = f(x - 2) + 2f(x-1)
Assume all numbers in the sequence before 1 are 0.
Therefore, we can substitute x with 6, because we are looking for the sixth number in the sequence.
f(6) = f(4) + 2f(5)
Since we know f(4) was 12 and f(5) was 29, we substitute those.
f(6) = 12 + 58
f(6) = 70
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