Complex sentence: The 2013 season was Rosenborg's 23rd consecutive year in Tippeligaen, their 46th season in the top flight of Norwegian football and first season with Per Joar Hansen as manager.
Split into simpler sentences: The 2013 season was Rosenborg's 23rd consecutive year in Tippeligaen, and their 46th season in the top flight of Norwegian football. It was their first season with Per Joar Hansen as manager.