2106572512 accurate to 1e-10.
    </p>
<p>
      For more accurate evaluations, we'll move to a multiprecision type and use
      a 20-point integration scheme:
    </p>
<pre class="programlisting"><span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">multiprecision</span><span class="special">::</span><span class="identifier">cpp_bin_float_quad</span><span class="special">;</span>

<span class="keyword">auto</span> <span class="ident