What was found
Flight 5167 from LEX to CLT; After takeoff the nose gear unsafe light stayed on. Gear was lowered and indicated down and locked. Aircraft returned to LEX and landed with no other problems. No emergency was declared. Maintenance from CLT inspected the nose gear and serviced it with nitrogen. Strut was fouund safe for ferry flight to CLT Flight # 9475. Maintenance in CLT removed and replaced the nose gear strut for not holding nitrogen. Retraction check C/W. Aircraft returned to service.