The center stage, in recurrence solving and summations, play hypergeometric
terms. Formally these are sequences annihilated by first order linear
recurrence operators. In simple words if we are given term \(a(n)\) then it is
hypergeometric if its consecutive term ratio is a rational function in \(n\) .
In mathematics, a factorial is a function applied to natural numbers greater than zero. The symbol for the factorial function is an exclamation mark after a number, like this: 2!