Timeline for Uniquely generate all permutations of three digits that sum to a particular value?
Current License: CC BY-SA 2.5
19 events
| when toggle format | what | by | license | comment | |
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| Sep 12, 2017 at 13:03 | answer | added | Malte | timeline score: 0 | |
| Dec 29, 2014 at 4:43 | answer | added | den.run.ai | timeline score: -1 | |
| Dec 6, 2012 at 0:23 | answer | added | Dave | timeline score: 0 | |
| Sep 11, 2010 at 0:30 | answer | added | user9149 | timeline score: 1 | |
| Sep 11, 2010 at 0:23 | answer | added | stokes91 | timeline score: 0 | |
| Aug 29, 2010 at 15:04 | answer | added | sleepless in beantown | timeline score: 1 | |
| Apr 30, 2010 at 15:44 | answer | added | Erik Garrison | timeline score: 2 | |
| Apr 29, 2010 at 15:44 | answer | added | Jacques Carette | timeline score: 5 | |
| Apr 28, 2010 at 0:56 | comment | added | Dan Piponi | Because @Mariano says this has nothing to do with generating functions I feel duty bound to point out that Mathematica will compute what you want using a generating function if you ask it for the coefficient of $t^k$ in $\prod_{i=1}^n 1/(1-tx_i^n)$. Each term corresponds to one of the sums you want, and you extract the $i$th digit of the sum by reading off the power of $x_i$ in that term. :-) | |
| Apr 27, 2010 at 23:57 | answer | added | Erik Garrison | timeline score: 2 | |
| Apr 8, 2010 at 5:12 | answer | added | Ross Tang | timeline score: 5 | |
| Dec 21, 2009 at 18:39 | comment | added | Joseph Malkevitch | For enumeration problems of this kind it is often of interest to have the consecutive items in the list (including between the last and first) be "near each other." This type enumeration is called a "Gray code," for Frank Gray who carried out an enumeration of this kind for the binary sequences of length n. For the binary sequences the idea was to have consecutive sequences have Hamming distance 1 between them. So the Gray code for this case is a Hamiltonian circuit on the n-cube. | |
| Dec 21, 2009 at 18:09 | answer | added | Greg Kuperberg | timeline score: 10 | |
| Dec 21, 2009 at 16:11 | comment | added | Michael Lugo | I removed the generating-functions tag. | |
| Dec 21, 2009 at 16:10 | history | edited | Michael Lugo |
removed generating-functions tag
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| Dec 21, 2009 at 16:06 | comment | added | Mariano Suárez-Álvarez | The 'generating-functions' tag is quite unrelated. | |
| Dec 21, 2009 at 15:50 | answer | added | Steve Huntsman | timeline score: 4 | |
| Dec 21, 2009 at 15:28 | history | edited | Alicia Garcia-Raboso |
edited tags
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| Dec 21, 2009 at 15:17 | history | asked | user2731 | CC BY-SA 2.5 |