# Next in series 1,4,2,8,2,16,... **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [June 26, 2014, 5:46pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713 "2014-06-26T17:46:15Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 27, 2014, 2:14pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/21 "2014-06-27T14:14:12Z")
The fact that the question is asking for the next _three_ numbers is probably the key to problem. So yeh, I’m thinking one 1, two 2s, three 3s… ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 27, 2014, 4:08pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/22 "2014-06-27T16:08:15Z")
Time for a hijack!!! Next in series: 20, 1, 18, 4, 13, … ---
**Author:** ![Sahirrnee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sahirrnee/32/13937_2.png) [@Sahirrnee](https://boards.straightdope.com/u/Sahirrnee)\ **Post date:** [June 27, 2014, 4:53pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/23 "2014-06-27T16:53:42Z")
20,1,18,4,13,9,3,16,-14,25,-40,36? ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 27, 2014, 4:59pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/24 "2014-06-27T16:59:40Z")
> [@Sahirrnee](#): > > 20,1,18,4,13,9,3,16,-14,25,-40,36? Nope, try again. (If you know the next few digits, please list them. But don’t reveal how you got the answer. 🙂 ) ---
**Author:** ![Sahirrnee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sahirrnee/32/13937_2.png) [@Sahirrnee](https://boards.straightdope.com/u/Sahirrnee)\ **Post date:** [June 27, 2014, 5:39pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/25 "2014-06-27T17:39:22Z")
Now I will go nutz trying to figure it out. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [June 27, 2014, 8:11pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/26 "2014-06-27T20:11:13Z")
> [@Dead\_Cat](#): > > You’re right, it isn’t obvious - it could equally be 1, 2, 2, 2, 3, 2, 4, 2, 5, 2, 6, 2… - a sequence that will probably be familiar to anyone who has played in an orchestra, especially brass or percussion! Please explain! I played sax in high school band but can’t figure what you’re alluding to here. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 27, 2014, 8:27pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/27 "2014-06-27T20:27:00Z")
> [@crafter\_man](#): > > time for a hijack!!! > > Next in series: > > 20, 1, 18, 4, 13, … …10, 6, 18? ---
**Author:** ![Stealth\_Potato](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Stealth\_Potato](https://boards.straightdope.com/u/Stealth_Potato)\ **Post date:** [June 27, 2014, 10:11pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/28 "2014-06-27T22:11:11Z")
I’m pretty sure it goes: 1, 4, 2, 8, 2, 16, 14 k of g in a f p d, … ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [June 28, 2014, 9:54am UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/29 "2014-06-28T09:54:19Z")
Here’s one of my favourites: 0, 1, 2, … The next number is … approximately 2.6 times 10^1746 – the series is the natural numbers starting with 0, each followed by n factorial signs: 0, 1!, 2!!, 3!!!, etc. It gets large very fast … ---
**Author:** ![SarahLiamJarvie](https://avatars.discourse-cdn.com/v4/letter/s/838e76/32.png) [@SarahLiamJarvie](https://boards.straightdope.com/u/SarahLiamJarvie)\ **Post date:** [June 28, 2014, 9:55am UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/30 "2014-06-28T09:55:47Z")
2,4,288 ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 28, 2014, 1:54pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/31 "2014-06-28T13:54:23Z")
> [@cmyk](#): > > …10, 6, 18? Nope. ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [June 28, 2014, 2:40pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/32 "2014-06-28T14:40:10Z")
The first impression I got was that the second number in the series is the product of (Sum of all the odd-sequenced integers)(4) while the odd numbered integers are a Fibonacci sequence. But a Fibonacci sequence has to begin 1, 1. If instead the odd numbered integers are calculated by having them appear in the same number they represent, then it goes 1 4 2 8 (1)(2)(4) 2 16 (1)(2)(2)(4) 3 48 (1)(2)(2)(3)(4) 3 142 (1)(2)(2)(3)(3)(4) 3 426 (1)(2)(2)(3)(3)(3)(4) 4 1704 (all that stuff times 4) … and so on. I don’t think there is any one correct answer, but does there have to be? Maybe the teacher’s just asking the students to play around and see what they get. ---
**Author:** ![Sahirrnee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sahirrnee/32/13937_2.png) [@Sahirrnee](https://boards.straightdope.com/u/Sahirrnee)\ **Post date:** [June 28, 2014, 4:36pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/33 "2014-06-28T16:36:40Z")
I hope the teacher will accept multiple answers if the student can show how (s)he got it. Once I had a test with the question 4 is to 6 as 6 is to? The correct answer was 8, but a significant number of us answered 9. When we explained how we got it the teacher accepted 8 or 9 as correct. As soon as I see 1,4 I want to go to 9,16,25,36 As soon as I see 1,3 I want to go to 7,11,13,17 ---
**Author:** ![ExTank](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@ExTank](https://boards.straightdope.com/u/ExTank)\ **Post date:** [June 28, 2014, 4:42pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/34 "2014-06-28T16:42:23Z")
> [@Crafter\_Man](#): > > Time for a hijack!!! > > Next in series: > > 20, 1, 18, 4, 13, … I hate these kind of questions. I think the next six numbers should be .357, .357, .357, .357, .357, .357! ---
**Author:** ![ExTank](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@ExTank](https://boards.straightdope.com/u/ExTank)\ **Post date:** [June 28, 2014, 5:35pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/35 "2014-06-28T17:35:35Z")
:smack: Eighteen numbers. Eighteen. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 28, 2014, 11:23pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/36 "2014-06-28T23:23:46Z")
> [@ExTank](#): > > I hate these kind of questions. I think the next six numbers should be .357, .357, .357, .357, .357, .357! > [@ExTank](#): > > :smack: Eighteen numbers. > > Eighteen. I was suspicious this wasn’t a self-contained sequence. :dubious: Now I don’t feel so bad. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [June 29, 2014, 12:15am UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/37 "2014-06-29T00:15:51Z")
1, 4, 2, 8, 2, 16, 219, 1002, 3063, … Seems pretty cut-and-dried. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [June 29, 2014, 10:07am UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/38 "2014-06-29T10:07:45Z")
> [@Crafter\_Man](#): > > Time for a hijack!!! > > Next in series: > > 20, 1, 18, 4, 13, … 6, 10, 15, … [here](http://en.wikipedia.org/wiki/File:Dartboard_diagram.svg) I haven’t played in years, yet saw it immediately. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [June 29, 2014, 7:27pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/39 "2014-06-29T19:27:09Z")
> [@dtilque](#): > > 6, 10, 15, … > > [here](http://en.wikipedia.org/wiki/File:Dartboard_diagram.svg) I haven’t played in years, yet saw it immediately. Clever, but these sorts of number sequence problems need to be self-contained (i.e. not dependent on context from anything else), but rather the next number derived from the numbers preceding it. ---
**Author:** ![Doctor\_Why\_Bother](https://avatars.discourse-cdn.com/v4/letter/d/e19adc/32.png) [@Doctor\_Why\_Bother](https://boards.straightdope.com/u/Doctor_Why_Bother)\ **Post date:** [June 29, 2014, 10:31pm UTC](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713/40 "2014-06-29T22:31:35Z")
Here’s a favourite of mine: 3,1,0,1,4,3,… Just carry the sequence on. As a little hint, it has a finite number of terms. [Previous page](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713.md?page=1) [Next page](https://boards.straightdope.com/t/next-in-series-1-4-2-8-2-16/691713.md?page=3)