IMO 1984 LL GBR28
A “number triangle” (tnk) (0 \leqk \leqn) is defined by tn,0 =
IMO 1984 LL GBR28
Origin: GBR
Problem
A “number triangle” (tnk) (0 \leqk \leqn) is defined by tn,0 = tn,n = 1 (n \geq0), tn+1,m = 2 − \sqrt m tn,m + 2 + \sqrt n−m+1 tn,m−1 (1 \leqm \leqn). Prove that all tn,m are integers.