Timeline for Does the set of happy numbers have a limiting density?

14 events

when toggle format	what		by	license	comment
Mar 10, 2017 at 9:42	history	edited	CommunityBot		replaced http://dl.dropbox.com/ with https://dl.dropbox.com/
Nov 10, 2011 at 22:55	answer	added	David Moews		timeline score: 8
Oct 19, 2011 at 5:43	vote	accept	Dave R
Oct 19, 2011 at 4:56	answer	added	Justin Gilmer		timeline score: 12
Oct 18, 2011 at 3:33	vote	accept	Dave R
Oct 19, 2011 at 5:43
Oct 16, 2011 at 3:34	answer	added	Gerry Myerson		timeline score: 4
Oct 16, 2011 at 3:31	answer	added	Joe Silverman		timeline score: 7
Oct 16, 2011 at 3:22	comment	added	GH from MO		@Ricky: It is decidable if a positive integer $n$ is happy. Indeed, $s(n)<n$ for $n\geq 1000$, therefore the sequence $n,s(n),s(s(n)),\dots$ contains some $m<1000$ twice which can be found by calculating enough terms of the sequence. If $m=1$ then $n$ is happy, otherwise it is unhappy.
Oct 16, 2011 at 3:19	comment	added	Dave R		My apologies. I fixed the error.
Oct 16, 2011 at 3:18	history	edited	Dave R	CC BY-SA 3.0	deleted 14 characters in body
Oct 16, 2011 at 3:05	comment	added	GH from MO		The orbit of $4$ is not $4\to 16\to 65\to 61\to 37\to\dots$, but $4\to 16\to 37\to\dots$.
Oct 16, 2011 at 2:58	comment	added	Spice the Bird		Interesting question. Where did the terminology of happy number come from?
Oct 16, 2011 at 2:55	comment	added	user5810		Is it decidable whether or not a positive integer is happy?
Oct 16, 2011 at 2:49	history	asked	Dave R	CC BY-SA 3.0