how to make this sequence on excel

[thunderspeed]

I want to make a sequence of the following in a certain column :

-1
1
-1
1
-1
1

how can I do that by dragging it down because I need 256 cells in the column to be like that

thanks in advance

[boopathiraja]

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[thunderspeed]

Thank you very very much boopathiraja

[morevijay1982]

input formula like this way

find attach sheet

[thunderspeed]

So if I want to make another column of a simillar sequence of -1s and 1s but in that way :

-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
its a 2^8 negative ones followed by 2^8 ones then again followed by 2^8 negative ones and so on , what modification to the line you gave me should I make to achieve so ?
thanks again

[boopathiraja]

tRY

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[thunderspeed]

Its still has a problem , if i type : =IF(MOD(QUOTIENT(ROW(),2^4),2)=0,1,-1)
it gives :
1
1
1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
so there are 3 ones at the beginning that I don't want in the sequnce , I need it to start right away from 16 negative ones then 16 ones and so on
Thanks in advance

[boopathiraja]

Try something like this if you are not starting it from 1st row

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[martindwilson]

=IF(iseven(CEILING(ROWS($A$1:A1)/2^3,1)),-1,1)
or
=IF(iseven(CEILING(ROWS($A$1:A1)/2^3,1)),1,-1) depending whether you want to start with - or +

[thunderspeed]

Thank you martindwilson very very much it worked great with the sequence, there is only a small error message with this green label on the cell , but values of sequence of negative and positive ones is totally right . So can I take the value of any cell and work with it and I think I shouldn't bother my self with this error .

thanks again , you rock