Series of sorts- Return 1 or 2 based on even or odd n

[connordurkin]

I would like to create a series where for each term if n is odd the term =1 and if n is even, the term = 2. I.e.

$a_{n} = 1 if \ n \ is \ odd \ and \ a_{n} = 2 \ if \ n \ is \ even$

 

[connordurkin]

Can anyone help me come up with some a_n such that this is true?

 

[Gackhammer]

So what you are saying is ...

For input n = 1,2,3,4,5...

a_n = 1,2,1,2,1,2There are a number of ways you can do this (click on Equations for Links )...

$2- n mod(2)$

$2-[sin^2(\frac{\pi n}{2})]$Just a couple that I thought off in my head...
One is discrete, one is continuous

 

[pwsnafu]

There is also $\frac{3+(-1)^n}{2}$