what is missing number in 3,5,13,43,177,?,5353

Question

find the missing number in this number line

 

Answer 1

3*1+2=5

5*2+3=13

13*3+4=43

43*4+5=177

177*5+6=891

891*6+7=5353

So, the missing number is 891.

 

P.S. Thanks, Kenneth! Well, I considered 3, 5, and 13, and different ways that we can get them from each other. The bigger numbers at the end of the list suggested that there should be multiplication involved. First I tried 3*2-1=5 and 5*3-2=13, but this didn't lead to a good pattern since 13*4-9=43 and 43*5-38=177. Then I tried this other thing that I wrote above and it worked.

Answer 2

Very clever, Somayeh.  Would you care to offer insight into how you worked it out & how long it took?