Forumla for this sequence

[Conrad11]

Hi there,

I am rubbish at maths, does anyone know/can work out the formula for this sequence?

1,2,4,8,16,32,64,128,256.......

i want to be able to get the nth term.

Thanks.

EDIT:

Is there even a formula.

 

[Ex-RoNiN]

for (x=1; x<n; x++)
{
x=x*2;
printf(x);
}

 

[.:MBK:.]

2^(n-1) i think...

 

[Conrad11]

for (x==1; x<n; x++)
{
x=x*2;
printf(x);
}

Could you please explain what is going on there?

 

[Una]

nth = 2^(n-1) I guess.

 

[neocon]

x^2 2^(n-1)
1 1 1
2 4 2
3 9 4
4 16 8
5 25 16
6 36 32
7 49 64
8 64 128
9 81 256
10 100 512

 

[Ex-RoNiN]

Could you please explain what is going on there?

It prints out your sequence

You start with 1. You times it by 2, you get 2, you print 2. Now you're at 2, you times it by 2, you get 4 and print 4, now you take your four and times them by 2, giving you 8, etc etc etc

 

[Conrad11]

Thanks for all the replies.

This formula worked fine:


2^(n-1)


Thanks again to everyone.

 

[Una]

for (x=1; x<n; x++)
{
x=x*2;
printf(x);
}

You realise that is so wrong on so many levels. Even if he was asking for the code for it.

 

[Zogger]

for (x=1; x<n; x++)
{
x=x*2;
printf(x);
}

I'm thinking that would print 2,6,14,30...

 

[Una]

I'm thinking that would print 2,6,14,30...

Nah it would segmentation fault before it even got that far, since printf takes a const char*

If you ignore that,

Say n = 6,

First iteration, x=1, x < n; x++ : x = x * 2 = 2. 2 Prints 2, Incremented by 1 = 3.
Second Iteration 3 < 6 true. 3*2 = 6 Prints 6. Increments 6++.
Terminates there.

So 2,6 etc.. yeah