Jason (jcreed) wrote,

Someone on /r/math posted a question which turned out to be a cute little puzzle. Which is to say, it trivially reduces to solving a pile of linear equations, but I found the answer a little surprising.

Is there is a way of putting the numbers 1 to 20 on 20-sided die such that there exists a constant K such that for every face f, the value on face f and the values of all three faces adjacent to f add up to K?

Here's (a perl script that outputs some octave code which computes) the answer

The thing that surprised me is that the face adjacency matrix of the icosahedron is actually nonsingular. I guess I expected it to be singular because of... symmetry or something? Dunno.
Tags: dice, math

  • (no subject)

    More things to add to the "chord progressions that aren't cliches-I-already-know-about nonetheless covertly appearing in multiple places" file.…

  • (no subject)

    Consider the chord motion in Lights's "Cactus In The Valley" that happens around 49s in: v link goes here | F G C C | F G C C | F G Am D7 | F G…

  • (no subject)

    Cute little synth widget playground: https://blokdust.com/

  • Post a new comment


    Anonymous comments are disabled in this journal

    default userpic

    Your reply will be screened

    Your IP address will be recorded