# Daniel Lemire's blog lemire.me

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 Post (required) * Required; the Post you're subscribing to. — All Comments/Replies — Jan 10th, 2009 6:08 pm — "Mark Reid" writes: Cute. That took me a minute or so before[...] Jan 10th, 2009 11:16 pm — "Geoff Wozniak" writes: I like that one. My wife didn’t get it[...] Jan 10th, 2009 11:24 pm — "Daniel Tunkelang" writes: It’s the opposite of an open problem. :-) Jan 10th, 2009 11:36 pm — "phd student" writes: thanks God I don’t have a phd yet, I w[...] Jan 10th, 2009 11:43 pm — "Michael Lugo" writes: 4444 = ? Jan 11th, 2009 2:00 am — "Karthik" writes: 2581 = 2? Jan 11th, 2009 2:44 am — "Mark Reid" writes: @Michael Lugo 4444 = 4 or 0, depending o[...] Jan 11th, 2009 1:56 pm — "David" writes: 2581 = 2 ? Jan 11th, 2009 6:39 pm — "Sui Fai John Mak" writes: The answer is 2. Here is the reason: The[...] Jan 12th, 2009 12:35 am — "Stephen Downes" writes: 2 Jan 12th, 2009 12:42 pm — "David" writes: I challenged a friend with this problem [...] Jan 14th, 2009 1:35 am — "Paranoid" writes: “My wife solved it” is much too grea[...] Jan 14th, 2009 1:36 am — "Paranoid" writes: (am I sexist or just psychologically wel[...] Mar 2nd, 2009 12:17 am — "Sammy" writes: First Betti number of the collection of [...] Jul 9th, 2011 7:54 pm — "man from Georgia" writes: we must count balls. consider 7662 here [...] Feb 9th, 2012 11:12 am — "keios" writes: Hi folks, so here’s my solution: 1. Le[...] Feb 9th, 2012 11:13 am — "keios" writes: Sorry: … 2 (other than 0)… Feb 11th, 2012 7:22 pm — "Maciek" writes: Bartek :) faktycznie Feb 11th, 2012 8:10 pm — "Bartek" writes: Hi. All we need is to count the number o[...] Feb 12th, 2012 9:40 pm — "Crowell" writes: 0=4 1=0 2=0 3=0 4 5=0 6=4 7=0 8 9=4 and [...] Feb 12th, 2012 9:41 pm — "Crowell" writes: sory, 8=8 :) Feb 13th, 2012 8:35 pm — "killyox" writes: There’s no maths here ! Just forms ! Y[...] Feb 16th, 2012 4:30 pm — "EmmaBlue" writes: Kylliox, you are a star. Thank you. I fi[...] Feb 19th, 2012 3:44 pm — "D" writes: I could not find the answer and I was go[...] Feb 22nd, 2012 5:18 pm — What i did was just define the numbers I[...] Feb 24th, 2012 9:01 am — "William Wu" writes: It is 2012 now… IT Person find the res[...] Feb 28th, 2012 5:23 pm — "David" writes: There is a ‘mathematical’ way to sol[...] Mar 3rd, 2012 11:52 am — "terrypin" writes: It’s now Saturday 3 March 2012. The Fa[...] Mar 7th, 2012 4:14 am — "Cindy" writes: Haha, it’s funny that people are mappi[...] Mar 16th, 2012 7:33 pm — "Mihai" writes: This is stupid, really :)) Mar 17th, 2012 1:06 pm — "johnpaul" writes: Simply count the closed loops… 8=2 clo[...] Mar 20th, 2012 9:37 am — "Andrew" writes: Or you could simply use a polynomial tha[...] Mar 20th, 2012 12:34 pm — "Daniel Lemire" writes: @Andrew Solving for a polynomial of degr[...] Mar 20th, 2012 11:12 pm — "Smola" writes: So, similar problem can be made with hor[...] Mar 21st, 2012 9:01 pm — "Sundar" writes: Hi Friends 1. Take a count of numbers ea[...] Mar 29th, 2012 12:27 am — "romadhoni" writes: you calculate it for too long and too co[...] Mar 30th, 2012 7:41 pm — "Tommaso" writes: Sundar, according to your rule I don’t[...] Apr 7th, 2012 2:00 pm — "irish joy PHD" writes: OMG.. this is so easy and youre having d[...] Apr 19th, 2012 4:03 am — "Christie" writes: I love how simple this was to solve, onc[...] Apr 28th, 2012 9:55 am — "thereFOUR" writes: I gave up after thinking 2 hours and rea[...] May 2nd, 2012 4:22 am — "Rodrigo" writes: “2581=?” 2581=2 8 tiene dos circulos[...] May 6th, 2012 2:27 pm — "HJ" writes: Crowell- I was fascinated by your answer[...] May 13th, 2012 4:41 am — "TB" writes: I got the answer to be 3, so I would say[...] Jun 3rd, 2012 7:21 pm — "J.C." writes: The only reason I figured this out was b[...] Nov 29th, 2012 8:59 am — 8: 8888=1# 7: 6,9,0-888=3×4=12# 6: 1,2,[...] Nov 29th, 2012 9:01 am — "gary wong" writes: 8: 8888=1# 7: 6,9,0-888=3×4=12# 6: 1,2,[...] Nov 29th, 2012 9:12 am — "gary wong" writes: by this logic, count from 0000 to 9999,t[...] Aug 11th, 2016 9:20 am — "boo xi" writes: the rule of a circle is the best rule, s[...] instantly hourly daily weekly Any value that is not `instantly` results in a digest instead of instant notifications.