A new Le Monde mathematical puzzle in the digit category:
Find the largest number such that each of its internal digits is strictly less than the average of its two neighbours. Same question when all digits differ.
For instance, n=96433469 is such a number. When trying pure brute force (with the usual integer2digits function!)
this is actually the largest number returned by the R code. There is no solution with 9 digits. Adding an extra condition
produces n=9520148 (seven digits) as the largest possible integer.
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