------
## 最终结论
```python
def modified_encode(sequence):
    result = []
    count = 1
    
    for i in range(len(sequence)):
        if i < len(sequence) - 1 and sequence[i] == sequence[i + 1]:
            count += 1
        else:
            if count > 1:
                result.append([count, sequence[i]])
            else:
                result.append(sequence[i])
            count = 1
            
    return result

# Test cases
assert modified_encode([1,1,2,3,4,4,5,1]) == [[2, 1], 2, 3, [2, 4], 5, 1]
assert modified_encode('automatically') == ['a', 'u', 't', 'o', 'm', 'a', 't', 'i', 'c', 'a', [2, 'l'], 'y']
assert modified_encode('python') == ['p', 'y', 't', 'h', 'o', 'n']
```