La Conjectura de Goldbach afirma que "Tot nombre enter parell superior a 2 es pot escriure com a suma de dos nombres primers" Aquesta conjectura, encara per desmostrar en general, el 2013 es va demostrar l'anomenada conjectura feble de Goldbach 271 anys després de la seva formulació pel matemàtic prussià Christian Goldbach el 1742. Posem alguns exemples: 6=3+3 12=5+7 42=5+37=11+31=13+29=19+23 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