Xi'an's Og

The riddle this week on The Riddler was about finding the largest sequence of integers between 1 and 100 such that each integer is only used once and always followed by a multiple or a factor. A basic R code searching at random [and programmed during a massive downpour on Skye] led to a solution of 69:

although there is no certainty this is the best p… And the solutions posted the next week showed sequences with length 77! [Interestingly, both posted solutions have a sequence starting with 87. And they seem to exploit the graph of connections between integers in a much more subtle way that my random exploration of subsequences.]

This entry was posted on August 10, 2017 at 12:17 am and is filed under Kids, R with tags division, mathematical puzzle, rain, Scotland, Skye, The Riddler. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.