You are given an array of integers where each element represents the height of a bar in a histogram. The bars are placed in the exact same sequence as given in the array. You need to find the area of the largest rectangle found in the histogram.

**Problem Note**

- The width of each bar is 1.
- You cannot change the sequence of bars.

**Example 1:**

```
Input: [2,1,5,6,2,3]
Output: 10
6
___
5 | |
___| |
| | |
| | |
| | | 3
| | | ___
2 | | | 2 | |
___ | | |___| |
| | 1 | | | | |
| |___| | | | |
| | | | | | |
| | | | | | |
-------------------------
Explanation:
6
___
5 | |
___|___|
|***|***|
|***|***|
|***|***| 3
|***|***| ___
2 |***|***| 2 | |
___ |***|***|___| |
| | 1 |***|***| | |
| |___|***|***| | |
| | |***|***| | |
| | |***|***| | |
-------------------------
```