\begin{tikzpicture}[scale=.5]
[font=\footnotesize] 
 \matrix(m) [matrix of math nodes,row sep={1.2em,between origins},column sep={1.2em,between origins},nodes in empty cells]{
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&\\
%&0&&0&&0&&0&&0&&0&&0&&&&&&&&&&&&&&&&\\
&1&&1&&1&&1&&1&&1&&1&&1&&&&&&&&&&&&&\\
6&&1&&4&&1&&2&&6&&1&&4&&1&&&&&&&&&&&&\\
&5&&3&&3&&1&&11&&5&&3&&3&&1&&&\node{\cdots};&&&\\
9&&14&&2&&2&&5&&9&&14&&2&&2&&5&&&&&&&&&&\\
&\textbf{25}&&\textbf{9}&&\textbf{1}&&\textbf{9}&&\textbf{4}&&\textbf{25}&&\textbf{9}&&\textbf{1}&&\textbf{9}&&\textbf{4}&&&&&&&&\\
&&16&&4&&4&&7&&11&&16&&4&&4&&7&&11&&&&&&&&\\
&&&7&&15&&3&&19&&7&&7&&15&&3&&19&&7&&&\node{\cdots};&\\
&&&&26&&11&&8&&12&&3&&26&&11&&8&&12&&3&&&&&\\
&\node{\cdots};&&&&19&&29&&5&&5&&11&&19&&29&&5&&5&&11&&&&&\\
&&&&&&\textbf{50}&&\textbf{18}&&\textbf{2}&&\textbf{18}&&\textbf{8}&&\textbf{50}&&\textbf{18}&&\textbf{2}&&\textbf{18}&&\textbf{8}&&&&\\
&&&&&&&31&&7&&7&&13&&21&&31&&7&&7&&13&&21&&&\\
&&&&&&&&12&&24&&5&&34&&13&&12&&24&&5&&34&&13&\\
&&&&&\node{\cdots};&&&&41&&17&&13&&21&&5&&41&&17&&13&&21&&5&\\
&&&&&&&&&&29&&44&&8&&8&&17&&29&&44&&8&&8&&\\
&&&&&&&&&&&\textbf{75}&&\textbf{27}&&\textbf{3}&&\textbf{27}&&\textbf{12}&&\textbf{75}&&\textbf{27}&&\textbf{3}&&\textbf{27}&\\
%&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&\\
&&&&&&&&&&&&&&&&&&&&&&
\node[rotate=-6.5]{\ddots};  %\node[rotate=-6.5,shift={(-0.034cm,-0.08cm)}]  {\ddots};%&&&&&&&&&&\node[rotate=-6.5,shift={(-0.034cm,-0.08cm)}]  {\ddots};
&&&&&\\
};


% \draw[opacity=0,rounded corners, fill=myblue,fill opacity=0.05] ($(m-1-1.south west)+(-0.15cm,0cm)$) -- ($(m-16-16.south west)+(-0.15cm,0cm)$)--($(m-16-26.south west)+(-0.15cm,0cm)$) -- ($(m-1-11.south west)+(-0.15cm,0cm)$) -- cycle;

% \draw[semithick,dashed,myblue,opacity=0.25] ($(m-1-1.south west)+(-0.15cm,0cm)$) -- ($(m-16-16.south west)+(-0.15cm,0cm)$);
% \draw[semithick,dashed,myblue,opacity=0.25] ($(m-1-11.south west)+(-0.15cm,0cm)$) -- ($(m-16-26.south west)+(-0.15cm,0cm)$);

% \draw[semithick,dashed,myblue,opacity=0.25] ($(m-1-1.south west)+(-0.15cm,0cm)$) -- ($(m-16-16.south west)+(-0.15cm,0cm)$);

% \draw[semithick,dashed,myblue,opacity=0.25] ($(m-1-1.south west)+(-0.15cm,0cm)$) -- ($(m-16-16.south west)+(-0.15cm,0cm)$);

%\draw[thick, dashed, black] (-21.5,4.1) -- (2,4.1);
%\draw[thick, dashed,black] (-15,-2.1) -- (8,-2.1);
%\draw[thick, dashed,black] (-9,-8.2) -- (11,-8.2);

\draw[dashed, fill=myred, fill opacity=0.25] (m-4-6) circle (0.57cm);
\draw[dashed, fill=myred, fill opacity=0.25] (m-9-11) circle (0.57cm);
\draw[dashed, fill=myred, fill opacity=0.25] (m-14-16) circle (0.57cm);
% \fill[myred,opacity=0.3] (m-9-11) circle (0.4cm);
% \fill[myred,opacity=0.3] (m-14-16) circle (0.4cm);

\draw[densely dotted, fill=mygreen, fill opacity=0.25] (m-2-2) circle (0.5cm);
\draw[densely dotted, fill=mygreen, fill opacity=0.25] (m-7-7) circle (0.5cm);
\draw[densely dotted, fill=mygreen, fill opacity=0.25]  (m-12-12) circle (0.5cm);
%  \fill[mygreen,opacity=0.3] (m-7-7) circle (0.4cm);
%  \fill[mygreen,opacity=0.3]  (m-12-12) circle (0.4cm);
\end{tikzpicture}