That's a good one, I hadn't thought of that. They're discussing A192787 over in the OEIS list. The problem was that the computer program was counting "1/2 + 1/3 + 1/6" and "1/3 + 1/2 + 1/6" as two different solutions. It was just a bug in the program. Regarding 1/1+1/-1+1/1, the definition of A192787: http://oeis.org/A192787 clearly says "Number of distinct solutions of 4/n = 1/a + 1/b + 1/c in positive integers.". So that's covered. On Tue, Feb 19, 2013 at 6:54 PM, Tom Rokicki <rokicki@gmail.com> wrote:
1/1 + 1/-1 + 1/1, perhaps? They say integer, not natural number.
On Tue, Feb 19, 2013 at 3:12 PM, meekerdb <meekerdb@verizon.net> wrote:
On 2/19/2013 1:36 PM, Allan Wechsler wrote:
Let A(n) be the number of ways of expressing 4/n as the sum of three integer reciprocals, where the mere permutation of a sum is regarded as not making a difference. [...]
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