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Affichage des articles du février, 2024

Concatenating two multiplications

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Today we'll explore the rules for a new (?) iteration a ) take any number N (say 10234567890) b ) replace all the zeros of N by ones (we get 11234567891) c ) make now the "O" multiplication (we multiply the odd digits; O = 1*1*3*5*7*9*1 = 945) d ) make now the "E" multiplication (we multiply the even digits; E = 2*4*6*8 = 384) e ) form the new number N using the concatenation OE (here N = 945384) and iterate; f ) if this leads to a single-digit N, or a 2-digit N like 12 or 21 (one odd digit, one even), square N and iterate. Example with the avatars of 12   12 --> 144  (we have squared 12)  144 --> 116  (we did 4*4 = 16)  116 --> 16   (we did 1*1 = 1)   16 --> 256  (we have squared 16)  256 --> 512  (we did 2*6 = 12, concatenated to 5)  512 --> 52   (we did 5*1 = 1)   52 --> 2704 (we have squared 52) 2704 --> 2714 (we have replaced 0 by 1) 2714 --> 78   (we did 7*1 = 7 an...