The Seidel-Entringer-Arnold triangle is the number triangle consisting of the Entringer numbers E_(n, k) arranged in "ox-plowing" order, E_0 E_10->E_11 E_22 <-E_21 <-E_20 E_30->E_31->E_32->E_33 E_44 <-E_43 <-E_42 <-E_41 <-E_40 giving 1 0->1 1<-1<-0 0->1->2->2 5<-5<-4<-2<-0