is beehaw related to lemmy?

  • 3 Posts
  • 38 Comments
Joined 1 year ago
cake
Cake day: June 8th, 2023

help-circle






  • Indeed, an integer is divisible by 3 if and only if the sum of its digits is divisible by 3.

    For proof, take the polynomial representation of an integer n = a_0 * 10^k + a_1 * 10^{k-1} + … + a_k * 1. Note that 10 mod 3 = 1, which means that 10^i mod 3 = (10 mod 3)^i = 1. This makes all powers of 10 = 1 and you’re left with n = a_0 + a_1 + … + a_k. Thus, n is divisible by 3 iff a_0 + a_1 + … + a_k is. Also note that iff answers your question then; all multiples of 3 have to, by definition, have digits whose sum is a multiple of 3





  • A flair-like implementation would be nice for certain communities. From past experience on reddit, I can see how it could be beneficial to filter a community’s posts through tags, say, to check latest announcements or new support questions. I’d personally prefer community-specific tags as opposed to global post tags (which is what I inferred from this post’s content, I haven’t read the RFC yet though) edit: the RFC talks about both instance-based tags and community-based tags, which is even better