/sci/ - Science & Math

[Anonymous No.3012186]

7,11,27,68,170,?
What number must be next and why?
I just can't figure it ;_;

[Anonymous No.3012211]

The n-th number is<div class="math">25-{\frac {457}{12}}\,n+{\frac {637}{24}}\,{n}^{2}-{\frac {89}{12}}\,{
n}^{3}+{\frac {23}{24}}\,{n}^{4}</div>
The next number is 392.

[Josef !!nUf2NflSAyw No.3012219]

>>3012211
Damn you, beat me to it ;(

[Anonymous No.3012232]

>>3012211
>>3012219
someone please explain me how to figure it just by looking at the numbers ;_;

[Anonymous No.3012248]

>>3012219
I like your code bro. How long have been learning Mathematica for?

[Anonymous No.3012249]

bump

[Anonymous No.3012250]

>>3012219
lol@that last postfix

[Josef !!nUf2NflSAyw No.3012274]

>>3012248
I've been (ab)using it for plotting, solving differential equations for quite some time, but I started actually programming in it maybe a year ago. I've been familiar with other languages (most notably C++ and PHP), but have never seen Mathematica as an alternative to those for solving math problems. I couldn't have been wronger.

>>3012250
Mathematica is godlike to write unreadable code <span class="math">\ddot\smile[/spoiler]

[Anonymous No.3012283]

>>3012274
I see thank for the info. I've known mathemtica for at least a year, but only use it sparingly so now that I see things like that really makes me feel even less proficient than before.

[Anonymous No.3012294]

>>3012232
>>3012232
>>3012232
>>3012232

[Josef !!nUf2NflSAyw No.3012306]

>>3012283
Well the calculation I've done is bullshit in the sense that I simply interpolated a polynomial through OPs numbers, which is of course not what he was looking for. It's a correct solution nevertheless (but so would a sequence of random complex numbers have been).

When you're learning Mathematica for the first time, you usually start at fancy graphics, nice plots and simplifying functions. That's the highest high level Mathematica has to offer, but it doesn't teach you much about the program.
If you want to work effectively with it (i.e. not use it as a plotting slave but for doing error analysis on nonlinear regression) you'll have to get an introduction from the other side: low to high. My first book was Shifrin, which might be a bit confusing to read sometimes, but it's easy to read otherwise, and it's for free: http://www.mathprogramming-intro.org/

[Anonymous No.3012307]

moar numbers
2,4,8,14,22,32,?
4,7,13,25,49,?
1,4,7,?,13,16
22,27,25,35,31,51,43,?
1,4,9,16,25,36,?
1,1,2,3,5,8,?
2,2,4,12,48,?
2,6,13,24,41,?

[Anonymous No.3012313]

>>3012274
at least you don't use expressions like
%%%%
like I do.

However, I have a present for your init.m file:

sexy[output_]:=Text[Style[output//Simplify,15,Hue[.64, 1, .7]]//TraditionalForm]

[Anonymous No.3012315]

That's numberwang!

[Josef !!nUf2NflSAyw No.3012322]

>>3012313 %%%%
I don't even know what this does. Is it the 4th-last result? I mean I feel bad when I'm using a single % already, I think you'll burn in hell for that hehe

[Anonymous No.3012323]

[Anonymous No.3012336]

>>3012323
Hallo deutschfag

[Anonymous No.3012343]

>>3012322
wegen %%%%

ja genau, bei mir würde es sich dann etwa so lesen

[Anonymous No.3012348]

[Anonymous No.3012353]

(okay, now I understand why you used Expand ^^)

[Josef !!nUf2NflSAyw No.3012354]

Stupid germanfags: see pic. umad?

>>3012343
Du hast wohl zu viel Assembler programmiert ;)
Ich hab früher auch ständig % benutzt, aber irgendwann ging's mir ziemlich aufn Sack dass ich mein halbes nb umschreiben musste wenn ich oben irgendwo ne Zeile eingefügt hab. Seitdem benutz ich es nur noch für kleine temporäre Hacks.

[Anonymous No.3012365]

Ihr hurrensöne könnt auch nur zahlen in euer programm eingeben ;_;
nur durch anschauen kanns keiner lösen

[Josef !!nUf2NflSAyw No.3012384]

>>3012365
Mit unseren Polynomen haben wir nichts getan außer uns über dich lustik zu machen. Dummkopf.

[Anonymous No.3012387]

>>3012384
oh habt ihrs mir aber voll gezeigt
;_; jetzt muss cih weinen

[Anonymous No.3012397]

How can a computer extrapolate patterns out via algorithms? is it creating polynomials that equal 7 at x=n, 11 at x=2*n and so on and so forth?

[Anonymous No.3012404]

>>3012397
yes

[Anonymous No.3012408]

>>3012397
>>3012404
Well, not exactly as you say, no. But yes: it just creates a polynomial.

[Anonymous No.3012413]

>>3012397
there are infinitely many answer to a question like op.
you want a polynomial which works with

7,11,27,68,170,9001

just type in the same alorithm with one more x.

[Anonymous No.3012429]

So it would fail if the pattern was something like

1,2,4,9,20,43,86,175

[start at 1, add the prime >= the current value]

like, i feel many patterns which humans could grasp would be very hard for a computer to come up with.

however the computer could and probably still would find it before the humans since it can brute force it basically. but i could see the computer coming up with many [maybe even infinite given enough time?] patterns that match the set of numbers, as long as the set of numbers is finite.

[Anonymous No.3012447]

>>3012429
> it would fail
That method would fail to correctly yield the next number. It would perfectly describe the numbers already given.

<span class="math">\frac{1}{252}x^{7} - \frac{7}{80}x^{6} + \frac{557}{720}x^{5} - \frac{163}{48}x^{4} + \frac{1159}{144}x^{3} - \frac{541}{60}x^{2} + \frac{1963}{420}x^{1} + 1[/spoiler]

[Josef !!nUf2NflSAyw No.3012444]

>>3012429
OPs question is idiotic, interpolating a polynomial through the points is idiotic. I don't see why we shouldn't do that.

[Anonymous No.3012454]

>>3012447
i was under the impression the whole point was to predict the next number.

i guess it could be useful to have a generating function to create the numbers that already exist though. Does this concept of patterns and calculating formula/predicting them have a name in math or the sciences? I know almost nothing about it but it seems pretty interesting.

[Anonymous No.3012457]

>So it would fail if the pattern was something like
>1,2,4,9,20,43,86,175
>[start at 1, add the prime >= the current value]
>add the prime

explain this pattern.
how do you even get to the number 2 and where did you use the prime 3?

[Anonymous No.3012463]

>>3012457
>assuming 1 is a prime, thats what he did

[Anonymous No.3012471]

>>3012457
start at 1.
1 is prime. 1+1=2
2 is prime.
2+2 = 4
4 is not prime. 5 is prime
4+5 = 9
9,10 not prime, 11 is prime
9+11=20
20+23 = 43
43+43=86

[Anonymous No.3012473]

>>3012307
2,4,8,14,22,32,44
4,7,13,25,49,97
1,4,7,10,13,16
22,27,25,35,31,51,43,83
1,4,9,16,25,36,49
1,1,2,3,5,8,13
2,2,4,12,48,240
2,6,13,24,41,67

Those are easy as fuck though.
Also, the sequence on the OP is from an IQ test and should therefore be humanly solvable without an expansion of a polynomial.
Try finding the calculation itself.

[Anonymous No.3012477]

>>3012454
Finding a function to fit existing data is kind of trivial. Finding the right one is outside the scope of mathematics. There are an infinite number of functions that will exactly match any set of points.

[Anonymous No.3012479]

>>3012463
oops i forgot that little property of unity. guess it would go 1,3,6,13,26

[Josef !!nUf2NflSAyw No.3012487]

Does anyone else get a have laugh at two things here?
a) People call interpolating polynomials a hard calculation
b) They really don't get how blatantly obvious we're humoring them with the polnomial solution

[Josef !!nUf2NflSAyw No.3012502]

By the way, the 101th prime is 104838000565921358787103165276, I simply extrapolated it from the first 100

[Anonymous No.3012506]

>>3012457
I don't think you understand what >= means. Or you don't understand that 2 is a prime number.

Start with 0. Nearest prime >= 0 is 1. 0+1=1
1. Nearest prime >= 1 is 1. 1+1=2
2. Nearest prime >= 2 is 2. 2+2=4
4. Nearest prime >= 4 is 5. 4+5=9
9. Nearest prime >=9 is 11. 9+11=20

[Anonymous No.3012512]

1 is not prime folks

[pascal !n5Z3VuZapw No.3012517]

>>3012502 implying an even number can be primr

[Josef !!nUf2NflSAyw No.3012522]

>>3012517
U mad, Riemann?

(I hope you're joking.)

[Anonymous No.3012525]

>>3012502

>even number
>a prime

[Anonymous No.3012526]

>>3012517
>implying 2 isn't prime

[pascal !n5Z3VuZapw No.3012533]

>>3012522
I thought all even numbers,were divisible by 2

[Anonymous No.3012536]

>>3012517

An even number can be a prime. Two is the only even number that is prime.

[Anonymous No.3012539]

This thread when from sad to pathetisad.

[pascal !n5Z3VuZapw No.3012540]

>>3012526
....

Oh right

[Anonymous No.3012551]

hurr durr

[Josef !!nUf2NflSAyw No.3012661]

>>3012533
Of course my huge ass number isn't a prime, that's the joke
dammit

[Anonymous No.3012682]

>>3012661

http://www.youtube.com/watch?v=PdFt3NEXcCY&feature=channel_video_title

[Josef !!nUf2NflSAyw No.3012696]

>>3012682
Wasn das schon wieder für Krebs

[Anonymous No.3012753]

>>3012696
geh zurück zum 4kanal.
ach..

[Anonymous No.3012794]

2,4,8,14,22,32,44
4,7,13,25,49,97
1,4,7,10,13,16
22,27,25,35,31,51,43,83
1,4,9,16,25,36, 49
1,1,2,3,5,8,13
2,2,4,12,48,240
2,6,13,24,41,66