Not sure of what your "double indexed variable means. One possible interpretation is a two-dimensionnal array of symbolic variables, flattened as needed :

```
sage: DIVar=[[var("alpha_%d_%d"%(u,v), latex_name="\\alpha_{%d,%d}"%(u, v)) for v in range(3)] for u in range(2)]
```

which is $$ \left[\left[{\alpha_{0,0}}, {\alpha_{0,1}}, {\alpha_{0,2}}\right], \left[{\alpha_{1,0}}, {\alpha_{1,1}}, {\alpha_{1,2}}\right]\right] $$

and can be used as:

```
sage: table([[f(u) for u in flatten(DIVar)] for f in (sin, cos, tan)], header_row=flatten(DIVar), header_column=[function("f")]+[sin, cos, tan])
f | alpha_0_0 alpha_0_1 alpha_0_2 alpha_1_0 alpha_1_1 alpha_1_2
+-----+----------------+----------------+----------------+----------------+----------------+----------------+
sin | sin(alpha_0_0) sin(alpha_0_1) sin(alpha_0_2) sin(alpha_1_0) sin(alpha_1_1) sin(alpha_1_2)
cos | cos(alpha_0_0) cos(alpha_0_1) cos(alpha_0_2) cos(alpha_1_0) cos(alpha_1_1) cos(alpha_1_2)
tan | tan(alpha_0_0) tan(alpha_0_1) tan(alpha_0_2) tan(alpha_1_0) tan(alpha_1_1) tan(alpha_1_2)
```

[ No LaTeX output here : the generated latex code uses `tabular`

, not understood by `ask.sagemath.org`

's Markdown. I know that there is a way to create an HTML version accepted here, but, for dear life, I'm unable to remember it... ].

HTH,

I think you should use

`'\\alpha'`

for the latex_name instead. Two slashes at the start because a backslash is a special character and needs to be "escaped". No trailing`_`

because Sage seems to insert that automatically in LaTeX names for indexed variables like this.Your example gives

oneindex. Can you give us an example with two indexes ?