Ray Arachelian wrote:
"Igor Chudov @ home" wrote:
Well, take 11, for example, it cannot be repsesented as a sum of different primes. It cannot, pure and simple.
Bullshit: 7+5+(-1)=11. Last I heard, negative numbers weren't excluded from being primes. 7 is different from 5, -1 is different from 7 and from 5.
If this is boiling down to a definition of primes, I'll haul out my Hardy & Wright, page 2: A number p is said to be prime if (i) p > 1, (ii) p has no positive divisors except 1 and p. ... It is important to observe that 1 is not reckoned as a prime. My number theory class at college (admittedly that was three decades ago) also started the prime series at 2 and went up from there. The term "odd primes" always meant 3 and above, not 1 and above. YMMV. -- Jim Gillogly 29 Blotmath S.R. 1998, 16:29 12.19.5.12.12, 4 Eb 5 Ceh, Ninth Lord of Night