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Possible Duplicate:
number of combination in which no two red balls are adjacent.

We have $N$ slots. They have to be filled with balls (either green or red), one ball for each slot. Green balls can not be placed in consecutive slots. Find the number of different arrangements.

Can some one help?

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marked as duplicate by Gerry Myerson, Leonid Kovalev, Chris Eagle, t.b., Asaf Karagila Aug 17 '12 at 15:14

This question was marked as an exact duplicate of an existing question.

I have answered the question today on this site, for white and red, with no two red in a row. – André Nicolas Apr 28 '12 at 6:33
Can you plz share the link..? – Muthukumar Apr 28 '12 at 6:34
Here it is – André Nicolas Apr 28 '12 at 6:35
Thanka you so much..! – Muthukumar Apr 28 '12 at 6:37
up vote 0 down vote accepted

It might have been useful, and not difficult, to find the number of possibilities for $N=1$, $N=2$, $N=3$, and perhaps $N=4$.

So that the question will not be listed as unanswered, here is the link to a solution of an essentially identical question.

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