````
% pandoc --webtex
$T_n={n+1 \choose 2}$
^D
<p><img style="vertical-align:middle" src="https://latex.codecogs.com/png.latex?%5Ctextstyle%20T_n%3D%7Bn%2B1%20%5Cchoose%202%7D" alt="T_n={n+1 \choose 2}" title="T_n={n+1 \choose 2}" class="math inline" /></p>
````

````
% pandoc --webtex
$$T_n={n+1 \choose 2}$$
^D
<p><img style="vertical-align:middle" src="https://latex.codecogs.com/png.latex?%5Cdisplaystyle%20T_n%3D%7Bn%2B1%20%5Cchoose%202%7D" alt="T_n={n+1 \choose 2}" title="T_n={n+1 \choose 2}" class="math display" /></p>
````