<p>Given three integers <code>x</code>, <code>y</code>, and <code>bound</code>, return <em>a list of all the <strong>powerful integers</strong> that have a value less than or equal to</em> <code>bound</code>.</p> <p>An integer is <strong>powerful</strong> if it can be represented as <code>x<sup>i</sup> + y<sup>j</sup></code> for some integers <code>i >= 0</code> and <code>j >= 0</code>.</p> <p>You may return the answer in <strong>any order</strong>. In your answer, each value should occur <strong>at most once</strong>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> x = 2, y = 3, bound = 10 <strong>Output:</strong> [2,3,4,5,7,9,10] <strong>Explanation:</strong> 2 = 2<sup>0</sup> + 3<sup>0</sup> 3 = 2<sup>1</sup> + 3<sup>0</sup> 4 = 2<sup>0</sup> + 3<sup>1</sup> 5 = 2<sup>1</sup> + 3<sup>1</sup> 7 = 2<sup>2</sup> + 3<sup>1</sup> 9 = 2<sup>3</sup> + 3<sup>0</sup> 10 = 2<sup>0</sup> + 3<sup>2</sup> </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> x = 3, y = 5, bound = 15 <strong>Output:</strong> [2,4,6,8,10,14] </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= x, y <= 100</code></li> <li><code>0 <= bound <= 10<sup>6</sup></code></li> </ul>