Find expert answers and community support for all your questions on IDNLearn.com. Ask any question and receive accurate, in-depth responses from our dedicated team of experts.

1,1,1,3,5,9,17,31.....

FIND OUT HOW MANY ODD NUMBERS ARE
IN THE PATTERN Befort THE 2021st NUMBER?


Sagot :

Answer:

2020

Step-by-step explanation:

The rule that this sequence follows is that each number is the sum of the last three numbers:

1+1+1=3

1+1+3=5

1+3+5=9

3+5+9=17

5+9+17=31

We can see that every number is going to be odd because they are always the sum of three odd numbers, and three odd numbers always add up to be another odd number (odd+odd+odd=even+odd=odd).

Therefore, if all the numbers in the sequence are odd, all the numbers before the 2021st number will be odd, so our answer is 2020.