<div style="padding:40px;color:#cbccc6"><h1>高斯圆问题</h1><p>计数半径 r 圆内整点。N(r) ≈ πr²。</p><div style="padding:20px;background:#0d1017;border-left:3px solid #ffb454"><span class="katex-error" title="ParseError: KaTeX parse error: Expected 'EOF', got '#' at position 8: N(r)=\\#̲\\{(x,y)\\in\\Z…" style="color:#cc0000">N(r)=\\#\\{(x,y)\\in\\Z^2:x^2+y^2\\le r^2\\}</span></div><p style="color:#707a8c">该页面需要 JavaScript 进行交互式可视化。</p></div>