title: How to use INDEX() inside ARRAYFORMULA()?
body: <p>I am trying to use the <code>INDEX()</code> formula inside an <code>ARRAYFORMULA()</code>. As a simple (non-sense) example, with 4 elements in column <code>A</code>, I expected that the following array formula entered in <code>B1</code> would display all four elements from <code>A</code> in column <code>B</code>:</p>
  
  <pre><code>=ARRAYFORMULA(INDEX($A$1:$A$4,ROW($A$1:$A$4)))
  </code></pre>
  
  <p>However, this only fills field <code>B1</code> with a the value found in <code>A1</code>.</p>
  
  <p>When I enter</p>
  
  <pre><code>=ARRAYFORMULA(ROW($A$1:$A$4))
  </code></pre>
  
  <p>in <code>B1</code>, then I do see all numbers 1 to 4 appear in column <code>B</code>. Why does my first array formula not expand similar like the second one does?</p>