HTML Code

<!DOCTYPE html>
<html lang=en>
<head>
  <meta charset=utf-8>
  <title>Power of 3 in range</title>
</head>
<body>
  <h1>Power of 3 in range 1 to 20</h1>
  <pre id=out></pre>
  <script>!function(){function n(n){if(n<=0)return!1;for(;n%3==0;)n/=3;return 1===n}var t,o=[];for(t=1;t<=20;t++)n(t)&&o.push(String(t));var e=[];e.push("Power of 3 in the range 1 to 20:"),e.push(o.join(" ")),document.getElementById("out").textContent=e.join("\n")}()</script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

JavaScript Power of 3 — Range 1 to 20 (Try It)