E140 flight crew experience loud bang in the nose shortly after takeoff. Suspect nose gear anomaly and land under emergency conditions at destination. Reporter notes a flight two days earlier encountered a landing gear retraction anomaly for which Maintenance was unable to find a cause.

Narrative

After departing ZZZ1; a loud sound was heard in the nose of the aircraft when accelerating from 200 kts to 250 kts. A decision was made to remain at 200 kts until we could evaluate the problem. After leaving the terminal area and established at our cruise altitude of 17;000 ft; we reviewed the AOM and determined the nose gear doors might not have retracted and/or there might be damage to the nose gear. All normal EICAS indications were present during initial gear retraction. The decision was made to continue to ZZZ2; execute a low approach; followed by an emergency landing. Factors involved with the decision were present position; time and distance to ZZZ2; aircraft weight; weather; runway length; familiarity with airport; and time needed to notify Dispatch; Maintenance; ATC; Flight Attendant; passengers; and prepare for approach. We declared an emergency; followed the emergency landing checklist; executed a low approach and landing to Runway XX at ZZZ2. All EICAS indications were normal during gear extension. ATC informed us after the low approach that 5 witnesses said gear looked good and one said nose gear was not straight. We landed successfully without incident. Normal steering and braking. Taxied to gate under own power. No passenger or crew injury and no visible aircraft damage. In December; a flight crew entered into the MEL that the landing gear malfunctioned after takeoff. Corrective action was entered into MEL. After flight event; ZZZ2 Maintenance recycled the gear 4 times and could not find a problem. Further inspection; examination; understanding; training of landing gear system should be addressed.