Question

1+(2 on exponent (n-1)) is always prime

True or False ?

Answer 1

true

Answer 2

False

Answer 3

It's always odd, but not prime

Answer 4

yeah n=4 gives 9

Answer 5

i swear i meant false! lol. i was thinking in my mind no way it can be true and accidently wrot down true

Answer 6

no problem yasmeen

Answer 7

\[1 + 2^{n-1}\]

= \[(1 +2) (2^{n-2} - 2^{n-3} ... + 1)\]

Answer 8

so it is always divisible by 3

Answer 9

so but 1+(2+(2) on exponent (n-1)) will be true ???

Answer 10

can you type that in the equation?

Answer 11

i think that is false too but

Answer 12

Do you know why the first one is false?

Answer 13

\[1+2*2^{(n-1)}\]

Answer 14

is always true

Answer 15

prime

Answer 16

\[1+ 2^n\]
no it's false

Answer 17

for n=3 is false

Answer 18

\[2^n + 1 = (2 +1) (2^{n-1} - 2^{n-2} ... + 1)\]

Answer 19

can be writing the primes in the form of exponent ?

Answer 20

but this only works if n is odd number
So if n is an odd number, it must be divisible by 3

Answer 21

and than every primes can be writeing like ... ?

Answer 22

nope
for \[n \ge 3\] and n is a odd number, it must have a factor of 3. So it must not be a prime number

Answer 23

but i like getting one formula with exponent for primes

do you lnow it ? please

Answer 24

or dont exist ?

Answer 25

do you kno

Answer 26

know

Answer 27

sorry for incorrect words

Answer 28

Check out this wikipedia page
http://en.wikipedia.org/wiki/Formula_for_primes

Answer 29

ok

Answer 30

thank you

Answer 31

no problem