title: Creating 4 back-to-back vectors of "A01 to A15" using paste0() in R?
body: <p>I'm wondering how to create 4 back-to-back, ordered vectors of characters each beginning from <code>"A01"</code> and ending in <code>"A15"</code> using <code>paste0</code> or a better regular expression code (see the full vector below)?</p>
  
  <p>I have tried the following (with no success):</p>
  
  <pre><code>rep(paste0("A", 0, 1:15), 4)
  </code></pre>
  
  <p>Here is the full vector I'm trying to achieve using <code>paste0</code>:</p>
  
  <pre><code>G = c("A01", "A02", "A03", "A04", "A05", "A06", "A07", "A08", "A09", "A10", "A11", "A12", 
        "A13", "A14", "A15", "A01", "A02", "A03", "A04", "A05", "A06", "A07", "A08", "A09", 
        "A11", "A12", "A13", "A14", "A15","A01", "A02", "A03", "A04", "A05", "A06", "A07", 
        "A08", "A09", "A12", "A13", "A14", "A15","A01", "A02", "A03", "A04", "A06", "A07", 
        "A08", "A09", "A12", "A13", "A14", "A15","A01", "A02", "A03", "A04", "A05", "A06", 
        "A07", "A08", "A09", "A10", "A11", "A12", "A13", "A14", "A15")
  </code></pre>