{"status": "success", "data": {"description_md": "For positive integers $n$, let $\\tau (n)$ denote the number of positive integer divisors of $n$, including $1$ and $n$. For example, $\\tau (1)=1$ and $\\tau(6) =4$. Define $S(n)$ by $$S(n)=\\tau(1)+ \\tau(2) + ... + \\tau(n). $$Let $a$ denote the number of positive integers $n \\leq 2005$ with $S(n)$ odd, and let $b$ denote the number of positive integers $n \\leq 2005$ with $S(n)$ even. Find $|a-b|$.\n___\nLeading zeroes must be inputted, so if your answer is `34`, then input `034`. Full credit goes to [MAA](https://maa.org/) for authoring these problems. These problems were taken on the [AOPS](https://artofproblemsolving.com/) website.", "description_html": "<p>For positive integers <span class=\"katex--inline\">n</span>, let <span class=\"katex--inline\">\\tau (n)</span> denote the number of positive integer divisors of <span class=\"katex--inline\">n</span>, including <span class=\"katex--inline\">1</span> and <span class=\"katex--inline\">n</span>. For example, <span class=\"katex--inline\">\\tau (1)=1</span> and <span class=\"katex--inline\">\\tau(6) =4</span>. Define <span class=\"katex--inline\">S(n)</span> by <span class=\"katex--display\">S(n)=\\tau(1)+ \\tau(2) + ... + \\tau(n).</span>Let <span class=\"katex--inline\">a</span> denote the number of positive integers <span class=\"katex--inline\">n \\leq 2005</span> with <span class=\"katex--inline\">S(n)</span> odd, and let <span class=\"katex--inline\">b</span> denote the number of positive integers <span class=\"katex--inline\">n \\leq 2005</span> with <span class=\"katex--inline\">S(n)</span> even. Find <span class=\"katex--inline\">|a-b|</span>.</p>&#10;<hr><p>Leading zeroes must be inputted, so if your answer is <code>34</code>, then input <code>034</code>. Full credit goes to <a href=\"https://maa.org/\">MAA</a> for authoring these problems. These problems were taken on the <a href=\"https://artofproblemsolving.com/\">AOPS</a> website.</p>", "hints_md": "", "hints_html": "", "editorial_md": "", "editorial_html": "", "flag_hint": "", "point_value": 5, "problem_name": "2005 AIME I Problem 12", "can_next": true, "can_prev": true, "nxt": "/problem/05_aime_I_p13", "prev": "/problem/05_aime_I_p11"}}