Closed-form formula for some recursively-defined integro-difference sequence of functions

Abstract

The main purpose of this paper is to derive the closed form solution the sequence $(g_n)_{n\in \mathbb{N}}$ of integro-difference equations that is defined recursively as follows: \begin{align*} g_1(x) & = \chi_{(-1/2, 1/2)} (x), g_{n+1}(x) & = g_n(x + 1/2)- g_n(x- 1/2) + \int_{x-\frac{1}{2}}^{x + \frac{1}{2}} g_n(s)ds, \, n\in \mathbb{N}, \end{align*} where $ g_1(x)= \chi_{(-1/2, 1/2)} (x) $ is the characteristic function of the unit interval $(-1/2, 1/2) $ has value equal to $ 1 $ on $(-1/2, 1/2) $ and $0$ elsewhere in $ \mathbb{R} $.