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<head>
  <meta charset="utf-8">
  <title>JS Number Pattern 55 - Try It (Compact)</title>
</head>
<body>
  <h1>Column-Wise Number Triangle (rows = 3)</h1>
  <p>Edit <code>rows</code> for a quick trace, then click Run.</p>
  <pre id="output"></pre>
  <script>
    const rows = 3;
    const tri = Array.from({ length: rows + 1 }, () => Array(rows + 1).fill(0));
    let num = 1;
    let result = "";

    for (let col = 1; col <= rows; col++) {
      for (let row = col; row <= rows; row++) {
        tri[row][col] = num;
        num++;
      }
    }

    for (let row = 1; row <= rows; row++) {
      let line = "";
      for (let col = 1; col <= row; col++) {
        line += tri[row][col];
        if (col < row) line += " ";
      }
      result += line + "\n";
    }

    document.getElementById("output").textContent = result;
  </script>
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JavaScript Number Pattern 55 (Try It — Compact rows = 3)