The problem is caused by the symbol of binomial coefficient (symbol of Newton), often used in math:

```
{N}\choose{k}
```

In my document I have formula:

```
$$ P(A) = \sum P(\{ (e_1,...,e_N) \}) = {N}\choose{k} \cdot p^kq^{N-k}$$
```

which is rendered as:

but should be:

## Best Answer

To fix this, simply add a pair of braces around the whole binomial coefficient, i.e.

(The braces around

`N`

and`k`

are not needed.)However, as you're using LaTeX, it is better to use

`\binom`

from`amsmath`

, i.e.Further, it is not recommended to use

`$$ ... $$`

, see Why is`\[ … \]`

preferable to`$$`

? Last, I'll note that`amsmath`

provides different commands for 'continuation dots', including`\dotsc`

for triple dots between commas.