an>
<span class="va">L1</span><span class="op">[</span><span class="fu"><a href="https://rdrr.io/r/base/cbind.html">cbind</a></span><span class="op">(</span><span class="fl">1</span> <span class="op">+</span> <span class="op">(</span><span class="fl">1</span><span class="op">:</span><span class="va">N</span><span class="op">)</span>, <span class="fl">1</span><span class="op">:</span><span class="va">N</span><span class="op">)</span><span class="op">]</span> <span class="op">&lt;-</span> <span class="st">"-a