Count the number of binary sequences with repeating initial segment; see http://math.stackexchange.com/questions/219552

Question219552.java

public class Question219552 {
    public static void main (String [] args) {
	for (int n = 2;;n += 2) {
	    int n2 = n >> 1;
	    long count = 0;

	    for (long bits = 0;bits < 1L << n;bits++) {
		outer:
		for (int l = 1;l <= n2;l++) {
		    for (int bit = 0;bit < l;bit++)
			if (((bits >> bit) & 1) != ((bits >> (bit + l)) & 1))
			    continue outer;
		    count++;
		    break;
		}
	    }
	    
	    System.out.println (n + " & " + count + " & " + ((1L << n) - count) + " & " + count / (double) (1L << n) + "\\\\");
	}
    }
}