Grid line doesn't have to be included
\documentclass[10pt]{beamer}
\usetheme{default}
\usepackage{graphicx}
\usepackage{amssymb,amsmath}
\usepackage{tikz}
\usetikzlibrary{matrix}
\usepackage{adjustbox}
\usepackage{caption} \
usepackage{subcaption}
\setbeamercolor{title}{fg=black}
\setbeamercolor{subtitle}{fg=gray}
\setbeamercolor{footlinecolor}{fg=white,bg=green}
\setbeamertemplate{footline}[text line]{% \parbox{\linewidth}{\vspace*{-10pt} \textit{Where Wall Street Goes to School} \hfill \insertpagenumber} } \setbeamertemplate{navigation symbols}{} –
\begin{tikzpicture}[>=stealth,sloped][scale=0.8]
\matrix (tree) [matrix of nodes, minimum size=0.25cm, column sep=2cm, row sep=1cm, ]
{ & $C_{i+1,j+1}$ \\ $C_{i,j}$ &$C_{i+1,j}$ \\
& $C_{i+1,j-1}$ \\
};
\draw[->] (tree-3-1) -- (tree-1-3) node [midway,above] {};
\draw[->] (tree-3-1) -- (tree-3-3) node [midway,above] {};
\draw[->] (tree-3-1) -- (tree-5-3) node [midway,below] {};
\end{tikzpicture}
\end{adjustbox} –