From a731a0362751507d4d77e2215610a762d416da21 Mon Sep 17 00:00:00 2001
From: Flancian <0@flancia.org>
Date: Thu, 11 May 2023 21:00:56 +0200
Subject: [PATCH] autopushed

---
 406.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/406.md b/406.md
index 42828f37c..1136027b5 100644
--- a/406.md
+++ b/406.md
@@ -3,3 +3,4 @@
 - [[203]] * 2 but then I'm stumped, 203 could be a prime. I hope it is, maybe?
 - It's clearly not divisible by 3 if you already checked [[406]] (sum of digits 10, not divisible by 3), but I still checked out of custom. While doing this, remembering which numbers you don't have to check is useful as it prevents duplicate work. Still I'm not concerned about repeating checks because I enjoy them.
 - There is a bound for possible divisors we have to check; the bound is the square root of 203. That means that we may have gained some equity by not having taken the square root of 406, potentially harder to calculate than that of 203.
+- In this case, though, the square root of 400 comes easier (to me): 20.