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<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JS Number Pattern 50 - Try It (User Input)</title>
</head>
<body>
  <h1>Rotating Number Pattern (User Input)</h1>
  <p>Enter n when prompted, then click Run.</p>
  <pre id="output"></pre>
  <script>
    const nInput = prompt("Enter n:");
    const n = parseInt(nInput, 10);
    let result = "";

    if (!Number.isFinite(n) || n < 1) {
      result = "Please enter a positive integer.";
    } else {
      for (let i = 1; i <= n; i++) {
        let line = "";
        for (let j = i; j > 1; j--) line += j;
        for (let k = 1; k <= n + 1 - i; k++) line += k;
        result += line + "\n";
      }
    }

    document.getElementById("output").textContent = result;
  </script>
</body>
</html>

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JavaScript Number Pattern 50 (Try It — User Input)