∫-∞∞Hm⁡(y)⁢ⅇ-y2⁢Hn⁡(x-y)⁢ⅇ-(x-y)2⁢ⅆ⁡y=π12⁢2-12⁢(m+n+1)⁢Hm+n⁡(2-12⁢x)⁢ⅇ-12⁢x2.