DENVER — Brock Nelson, like most people who have watched the Islanders for the past decade, keeps catching himself when he sees highlights of this year’s team. He notices No. 29, and it takes a moment to compute. “I feel like I’m so programmed to see 29 and think of myself,” Colorado’s No. 11, né 29 with the Isles, said Sunday before facing the Islanders for the first time in an eventual 4-1 win for his new team . “It’s weird.” Jonathan Drouin, the player wearing 29 in blue and orange this