Info from a person living in Denmark:
A train leaves every hour XX:40 from Copenhagen Airport to Odense. You do not need to change trains.
From Copenhagen Central Station train departs to Odense as follows:
monday-fridays:
xx:56 (only one stop) duration approx 1:20
xx:00 (5 stops) duration approx. 1:35
xx:30 (7 stops) duration approx. 1:40
on saturday/sundays it is the same, except the xx:56 does not operate.
two classes onboard the trains: Business and Standard. - Despite whatever country you come from, sitting in "standard" is perfect. The condition of the trains are very good and it is a beautiful trip. During the journey you will run through a tunnel (under the water) for approx 7km and a bridge for approx 10 km (can't remember the figures).
Ine Business you will get bread in the morning, and a small biscutt during the rest of the day. You will have free coffee/tea/orange juice/water during the trip.
From Copenhagen Airport trains leaves during the day:
XX:06
xx:26
XX:46
more infrequent during the night.
Ask if you need more questions.