Fibonacci Series
Fibonacci first 10 numbers are
1, 1, 2, 3, 5, 8, 13, 21, 34, 55
Method
Take the previous 2 numbers. Add them together. They get the next number in the Fibonacci series. 34 + 55 = 89
First Name
Leonardo
Stretch
Show 300 is not in this series
4 7 10 13 16 ... in general y = 4 + (n-1)d
n can be any positive number starting at 1. 300 is not in the series because no number in the series is divisible by 3. d = 3 and n can be either divisible by 3 or not. It doesn't matter. 4 added to the result of (n - 1)*d will give a number not divisible by 3.
Series
A
7 10 13 16 19 ... tn = 7 + (n-1)*3 .... n ≥ 1
B
8 20 32 44 56 ... tn = 8 + (n - 1)*12 ... n≥1
C
4 1 -2 -5 - 8 ... tn = 4 + (n - 1)*(-3) .... n ≥1
I'll leave the last 2 to you. They look just like the ones above.