1<?xml version='1.0'?> 2<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN' 3 'http://www.w3.org/TR/MathML2/dtd/xhtml-math11-f.dtd' 4 [<!ENTITY mathml 'http://www.w3.org/1998/Math/MathML'>]> 5<html xmlns='http://www.w3.org/1999/xhtml'> 6<head><title>zeta8</title> 7<!-- MathML created with MathCast Equation Editor version 0.89 --> 8</head> 9<body> 10<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> 11 <mrow> 12 <mi>ζ</mi> 13 <mfenced> 14 <mrow> 15 <mo>−</mo> 16 <mn>2</mn> 17 <mi>n</mi> 18 </mrow> 19 </mfenced> 20 <mo>=</mo> 21 <mn>0</mn> 22 <mspace width="1em"/> 23 <mo>;</mo> 24 <mspace width="1em"/> 25 <mi>n</mi> 26 <mo>∈</mo> 27 <mi>ℕ</mi> 28 </mrow> 29</math> 30</body> 31</html>