Consider the sequence \(5,11,19,29,41,55, \ldots\) Assume \(a_{1}=5\)
(a) Find a closed formula for \(a_{n},\) the \(n\) th term of the sequence, by
writing each term as a sum of a sequence. Hint: first find \(a_{0},\) but ignore
it when collapsing the sum.
(b) Find a closed formula again, this time using either polynomial fitting or
the characteristic root technique (whichever is appropriate). Show your work.
(c) Find a closed formula once again, this time by recognizing the sequence as
a modification to some well known sequence(s). Explain.