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>polygamma1</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 <msup> 13 <mi>ψ</mi> 14 <mfenced> 15 <mrow> 16 <mi>n</mi> 17 </mrow> 18 </mfenced> 19 </msup> 20 <mfenced> 21 <mrow> 22 <mi>x</mi> 23 </mrow> 24 </mfenced> 25 <mo>=</mo> 26 <msup> 27 <mfenced> 28 <mrow> 29 <mo>−</mo> 30 <mn>1</mn> 31 </mrow> 32 </mfenced> 33 <mrow> 34 <mi>n</mi> 35 <mo>+</mo> 36 <mn>1</mn> 37 </mrow> 38 </msup> 39 <mi>n</mi> 40 <mo>!</mo> 41 <munderover> 42 <mo>∑</mo> 43 <mrow> 44 <mi>k</mi> 45 <mo>=</mo> 46 <mn>0</mn> 47 </mrow> 48 <mi>∞</mi> 49 </munderover> 50 <mfrac> 51 <mn>1</mn> 52 <mrow> 53 <msup> 54 <mfenced> 55 <mrow> 56 <mi>k</mi> 57 <mo>+</mo> 58 <mi>x</mi> 59 </mrow> 60 </mfenced> 61 <mrow> 62 <mi>n</mi> 63 <mo>+</mo> 64 <mn>1</mn> 65 </mrow> 66 </msup> 67 </mrow> 68 </mfrac> 69 <mo>=</mo> 70 <mfrac> 71 <mrow> 72 <msup> 73 <mo>∂</mo> 74 <mi>n</mi> 75 </msup> 76 <mi>ψ</mi> 77 <mfenced> 78 <mrow> 79 <mi>x</mi> 80 </mrow> 81 </mfenced> 82 </mrow> 83 <mrow> 84 <msup> 85 <mo>∂</mo> 86 <mi>n</mi> 87 </msup> 88 <mi>x</mi> 89 </mrow> 90 </mfrac> 91 </mrow> 92</math> 93</body> 94</html>