An A320 Captain reported that after takeoff the landing gear did not retract and a reverser unlock ECAM alerted. After completing the QRH and Supplemental procedures the landing gear retracted and crew continued to its destination.

Narrative

Landing gear failed to retract after take-off. ECAM message for 'gear not uplocked' and 'landing gear doors open'; also 'eng 2 reverser fault'. I asked ATC for a level off at 3000 ft and for an extended right down wind and told ATC that we will need to return to the airport. The First Officer placed the gear handle in the down position. We then went through the QRH and non-normal supplemental book. Following the non-normal supplemental book for the ECAM messages we recycled the landing and this time the gear retracted. The gear indications were back to normal. I then decided not to return to the departure airport but to continue on to our destination since the gear was up and no fault messages were present. I felt it was safer to continue on because I would be landing 9000 lbs over weight if we landed at our departure airport. After reaching cruise I talked to Dispatch and Maintenance Control; they agreed that continuing was the best course of action to take. Landed with no problems. Right main landing gear sensor failed momentarily.