Timeline for Evaluation of a combinatorial sum (that comes from random matrices)
Current License: CC BY-SA 2.5
13 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 7, 2010 at 12:25 | comment | added | Pietro Majer | why don't you? I posted an answer to stimulate other contributions... ;-) | |
| Jul 6, 2010 at 23:16 | comment | added | Wadim Zudilin | At the end I find your identity surprising enough. +1. And 2 answers already, so I don't need to think of it. :-) | |
| Jul 6, 2010 at 23:08 | answer | added | David E Speyer | timeline score: 5 | |
| Jul 6, 2010 at 22:33 | answer | added | Pietro Majer | timeline score: 3 | |
| Jul 4, 2010 at 11:25 | comment | added | Brad Rodgers | Ah, maybe that was Wadim's confusion as well. Probably the clarifying remark under the sum actually added confusion in retrospect. I made one more edit changing 'ordered set' to 'sequence.' | |
| Jul 4, 2010 at 11:22 | history | edited | Brad Rodgers | CC BY-SA 2.5 |
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| Jul 4, 2010 at 9:22 | comment | added | darij grinberg | I'm just realizing how messed up combinatorics must be when the word "ordered" may mean two completely different things... (I first thought it meant $p_0\geq p_1\geq ...$) | |
| Jul 4, 2010 at 0:55 | comment | added | Brad Rodgers | Or more concretely: for r=2, the situation is to sum over the following sets for $(p_0,p_1,...)$: (2,0,0,...), (0,2,0,0,...), (0,0,2,0,...),... ;(1,1,0,0,...), (1,0,1,0,0...), ... ;(0,1,1,0,0,...), (0,1,0,1,0,...),...; ... Using partial fractions, it is not difficult to see that sum over all these entries is 1/2. | |
| Jul 4, 2010 at 0:26 | history | edited | Brad Rodgers | CC BY-SA 2.5 |
added 209 characters in body; added 45 characters in body
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| Jul 4, 2010 at 0:11 | comment | added | Brad Rodgers | I've written it slightly differently in an edit at the bottom; let me know if this is more transparent. | |
| Jul 4, 2010 at 0:08 | history | edited | Brad Rodgers | CC BY-SA 2.5 |
added 207 characters in body
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| Jul 3, 2010 at 23:28 | comment | added | Wadim Zudilin | It's probbably to early for me, but I can't follow the pattern of your summand. I would guess that writing it clearly is a half of solution... | |
| Jul 3, 2010 at 22:51 | history | asked | Brad Rodgers | CC BY-SA 2.5 |