an>, <span class='fl'>15</span>)
<span class='fu'>ncombinations</span>(<span class='fl'>40</span>, <span class='fl'>15</span>, <span class='kw'>bigz</span> <span class='kw'>=</span> <span class='fl'>TRUE</span>)</div><div class='output co'>#&gt; Big Integer ('bigz') :
#&gt; [1] 40225345056</div><div class='input'>
<span class='co'># number of combinations of `c("a", "b", "b")`</span>
<span class='co'># they are `c("a", "b")` and `c("b", "b")`</span>
<span class='fu'>ncombinations</span>(<span class='kw'>k</