5 £ f.'f & 5 W Ty : Wflfizm*flmiq&kufihflqmuw‘.mw »“IM'MW? i ' b u L LR e A TR RN T SR | it R T PO R P T T oY TP ! - T 2ol Al LR R R S bk L Lt 56 THE FASCINATION OF NUMBERS series; there is instead a pair of numbers and these are respectivelv 1 less and 1 greater than n®-1. For 44, the central pair of numbers are 63 and 65 (that is, 64—1 and 64+1) respectively, so that: 4*=61-+63+65+67=256 There is a simple reason why this relationship should exist. If an odd number has a factor, then if it be divided by that factor, we can represent it as the sum of its parts, thus: 93=31+3I+3I If we deduct 2 from the first of these parts and add 2 to the last, we obtain: 93=29+3I+33 which is obviously the same. In the same way, any even number may be divided into equal parts: 64=16416416416 This time we deduct g from the first term and add 3 to the last term; and deduct 1 from the second term and add 1 to the third term, so that: 64=13+15+17+19 This property of divisibility and convertibility to terms of odd numbers is possessed by most composite numbers. An important fact which emerges, however, is that no prime number can be treated in the same way, for the simple reason that they have no factors other than themselves and unity. This suggests a new way for identifying primes. Let us first examine those numbers which can be built up from the odd number series. We find that all these are com- posite numbers. For the numbers 1 to 50, we obtain the fol- lowing results: Derived from the odd series 1, 4, 8, 9, 12, 15, 16, 20, 21, 24, 25, 27, 28, 32, 33, 35, 36, 39, 40, 44, 45, 48, 49