Math Puzzle: Finish the CycleNEWS | 28 March 2025Eight numbers emerge in sequence according to a certain system. One number is unknown. Can you figure out what it should be?
Show puzzle solution Each number is the sum of the squares of the digits of its predecessor. 42 = 16 → 12 + 62 = 37 → 32 + 72 = 58 → 52 + 82 = 89 → 82 + 92 = 145 → 12 + 42 + 52 = 42 → 42 + 22 = 20 → 22 + 02 = 4 The missing number is 20.
We’d love to hear from you! E-mail us at games@sciam.com to share your experience.
This puzzle originally appeared in Spektrum der Wissenschaft and was reproduced with permission.Author: Heinrich Hemme. Source
