INDIANAPOLIS — The Lakers seemed bent on delivering a serious payback to the Indiana Pacers in the first half of tonight’s game. They led by as many as 24 points and shot 61 percent in the first half. Pau Gasol scored 21 points on 9-for-11 shooting and grabbed six rebounds. Lamar Odom added 12 points on 5-for-7 shooting plus seven rebounds. The Pacers defeated the Lakers last month at Staples Center.