Euler's continued fraction formula

(mathematics) A formula connecting a finite sum of products to a finite continued fraction: a_0+a_0a_1+a_0a_1a_2+⋯+a_0a_1a_2⋯a_n= cfrac a_0 1- cfrac a_1 1+a_1- cfrac a_2 1+a_2- cfrac ddotsddots cfrac a_n-1 1+a_n-1- cfrac a_n 1+a_n,.