please slove 1,3,7,15,31,...?

Question

please show me how to find An (or f(x)) of
sequence 1,3,7,15,31,........

Answer 1

Its (2^n)-1.

The first digit is 1 so (2^1)-1=1.
Similarly (2^2)-1=3 and so on.

Answer 2

The function f(x) = 2^n + 2^n - 1

If n = 0, f(x) = 2^0 + 2^0 - 1 = 1 + 1 - 1 = 1
If n = 1, f(x) = 2^1 + 2^1 - 1 = 2 + 2 - 1 = 3
If n = 2, f(x) = 2^2 + 2^2 - 1 = 4 + 4 - 1 = 7
If n = 3, f(x) = 2^3 + 2^3 - 1 = 8 + 8 - 1 = 15
If n = 4, f(x) = 2^4 + 2^4 - 1 = 16 + 16 - 1 = 31
If n = 5, f(x) = 2^5 + 2^5 - 1 = 32 + 32 - 1 = 63
and SO ON....

Answer 3

from 1 to 3 is 2
from 3 to 7 is 4
from 7 to 15 is 8
from 15 to 31 is 16
threfore:
3 - 1= 2
2 x 2 = 4
4 + 3 = 7
7 - 4 = 3
3 x 2 = 6
6 + 7 = 13

Answer 4

Working out by Algebra

Outputs(M)- 1,3,7,15,31...

Inputs(n)- first in sequance, second in sequence...

Formula- M= 2^n -1

next in the sequence is, 63, 127, 255 etc.

Just use the formula

Answer 5

note the difference begins 2^1
2^2
2^3
2^4

or you should have seen 2 4 8 16
and then figured 2 squared - 2 cubed etc

Answer 6

think of of those styles of math question in different words. for occasion interior the 1st question... 5h+2-h=22 the 1st concern yo desire to do is integrate tems that are alike. so we could basically rearrange what you have already got. 5h-h+2=22 next in case you desire to flow an merchandise on the different facet of the = sign the article variations signs and indicators. So if the article have been -3 it is going to become +3 on the different facet and no count if it is +3 then it is going to become -3. So.... 5h-h=22-2 next we could desire to integrate some extra.... whilst coping with factors like 5x, 5xy, 5anything, basically say to your self... I even have 5 h's minus a million h So... 4h=20 the appropriate step in this technique, is calling your self the question, "4 prolonged via what quantity equals 20???" If the question is extra stable like 32h=224, then we are able to apply the long hand approach. What you do in eiher case is the comparable, yet one in each of them we are able to do in our head. to make sure what h is we attempt to get h all via itself on one facet of the = sign. we try this via deviding the two factors of the equation via the comparable quantity. we could desire to compliment a quantity which will make the 4 flow away. once you devide any quantity via itself the respond is usually a million. So...... 4h/4 = 20/4 SO..... h=5

Answer 7

1,3,7,15,31,63,124,249,etc

1&3&3=7
1&7&7=15
1&15&15=31
1&31&31=63
1&63&63=124
1&124&124=249
etc.

Answer 8

The n-th number in the sequence is sum 2^k k=0 to k=n-1, which is equivalent to (2^n) -1. I'll leave the rest of your homework to you.

Answer 9

f(1) = 1 = 2 (1) - 1
f(2) = 3 = 2 (2) - 1
f(3) = 5 = 2(3) -1
f(n) = 2n-1

Answer 10

n+(n+1)=2n+1
1
1+(1+1)=3
3+(3+1)=7
7+(7+1)=15
15+(15+1)=31
31+(31+1)=63