Functions

Which one of the following is the closed form for the generating function of the sequence \{a_n \}_{n \geq 0} defined below?
a_n= \left \{ \begin{matrix} n+1, &n \text{ is odd} \\ 1,& \text{otherwise} \end{matrix} \right.

Consider the following sets, where n\geq 2:

S1: Set of all nxn matrices with entries from the set \{a, b, c\}
S2: Set of all functions from the set\{0,1,2,...,n^2-1\} to the set \{0, 1, 2 \}

Which of the following choice(s) is/are correct?
[MSQ]

If the ordinary generating function of a sequence \{a_{n}\}_{n=0}^{\infty} \; is \; \frac{1+z}{(1-z)^{3}} then a_{3}-a_{0} is equal to ______.

If g(x)=1-x and h(x)=\frac{x}{x-1}, then \frac{g(h(x))}{h(g(x))} is:

Let A be a finite set having x elements and let B be a finite set having y elements. What is the number of distinct functions mapping B into A.

Consider the set of all functions f:{0,1,...,2014}\rightarrow{0,1...,2014} such that f(f(i))=i, for 0\leqi\leq2014 . Consider the following statements.
P. For each such function it must be the case that for every i, f(i) = i,
Q. For each such function it must be the case that for some i,f(i) = i,
R. Each such function must be onto.
Which one of the following is CORRECT?

Let S denote the set of all functions f:{\{0,1\}}^{4} \rightarrow \{0,1\}. Denote by N the number of functions from S to the set {0,1}. The value of log_{2} log_{2}N is______.

How many onto (or surjective) functions are there from an n-element ( n \geq 2 ) set to a 2-element set?

Let f be a function from a set A to a set B, g a function from B to C, and h a function from A to C, such that h(a) = g(f(a)) for all a \in A. Which of the following statements is always true for all such functions f and g?

Let f: B \rightarrow C and g: A \rightarrow B be two functions and let h = f\cdotg. Given that h is an onto function which one of the following is TRUE?