The ideas of linear recurrences show how some of the summation formulasi = Let an(+2)(n+1)(n), and observe that a = -1+n-3n + 2n is a non-homogeneous linear recurrence with initial condition = 0. (a) Show that a must be a polynomial function of n with degree 4. (b) Determine the coefficients of this polynomial. Check that this is the same formula you would obtain by using the table of summations