Suppose you want some MathML like this:
<?xml version="1.0" encoding="UTF-8"?>
<math xmlns="http://www.w3.org/1998/Math/MathML">
<mrow>
<mi>f(1)</mi>
<mo>=</mo>
<mn>1</mn>
</mrow>
<mrow>
<mi>f(2)</mi>
<mo>=</mo>
<mn>1</mn>
</mrow>
<mrow>
<mi>f(3)</mi>
<mo>=</mo>
<mn>2</mn>
</mrow>
</math>