Try
flirc_util.exe sendir --pattern=0,8834,4157,509,1534,510,494,509,493,507,495,508,1536,509,494,509,493,509,494,508,495,509,493,535,469,508,495,506,495,510,493,507,496,508,496,508,1534,509,495,522,480,507,496,508,494,508,495,509,494,509,493,508,1534,509,494,508,495,507,495,508 --repeat=0
Close Flirc GUI before running the command.
--raw and --pronto arguments are not available before version 3.26.8.