The binary operator $$ \ne $$ is defined by the following truth table.

p	q	p$$ \ne $$q
0	0	0
0	1	1
1	0	1
1	1	0

Which one of the following is true about the binary operator $$ \ne $$?

Consider a 4-bit Johnson counter with an initial value of 0000. The counting sequence of this counter is

Let $${a_n}$$ represent the number of bit strings of length n containing two consecutive 1s. What is the recurrence relation for $${a_n}$$?

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