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>digamma4</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>ψ</mi> 13 <mfenced> 14 <mrow> 15 <mi>n</mi> 16 </mrow> 17 </mfenced> 18 <mo>=</mo> 19 <munderover> 20 <mo>∑</mo> 21 <mrow> 22 <mi>k</mi> 23 <mo>=</mo> 24 <mn>1</mn> 25 </mrow> 26 <mrow> 27 <mi>n</mi> 28 <mo>−</mo> 29 <mn>1</mn> 30 </mrow> 31 </munderover> 32 <mfrac> 33 <mn>1</mn> 34 <mi>k</mi> 35 </mfrac> 36 <mo>−</mo> 37 <mi>γ</mi> 38 <mspace width="1em"/> 39 <mo>;</mo> 40 <mspace width="1em"/> 41 <mi>n</mi> 42 <mo>∈</mo> 43 <mi>ℕ</mi> 44 </mrow> 45</math> 46</body> 47</html>