Pythagoras discovered the smallest pair of amicable numbers: 220 and 284. The Arab mathematician Al-Banna found a larger amicable pair, 17,296 and 18,416, but European mathema

…ticians were not aware of this discovery. Pierre de Fermat rediscovered this amicable pair in 1636. Rene Descartes rediscovered another amicable pair known to Arab mathematicians in 1638 - the pair 9,363,584 and 9,437,056. Leonhard Euler found 30 pairs of amicable numbers by 1747 because he developed a formula that could produce amicable pairs. B. Nicolo I. Paganini found the smaller amicable pair 1184 and 1210 that had been missed by other European mathematicians in 1866. ( Full Answer )