18/01/30 09:48:47.26 tDXdTeaU.net
>>327
>2. {a,b,c}={1,r,r^2} (a-1)(c-1)=0
{a,b,c}={m^2,mn,n^2} (a-1)(c-1)=(m^2-1)(n^2-1)
{m,n}={2k,2k+1} (m^2-1)(n^2-1)=(4k^2-1)4k(k+1)
2|k(k+1) 8|4k(k+1)
18/01/30 09:48:47.26 tDXdTeaU.net
>>327
>2. {a,b,c}={1,r,r^2} (a-1)(c-1)=0
{a,b,c}={m^2,mn,n^2} (a-1)(c-1)=(m^2-1)(n^2-1)
{m,n}={2k,2k+1} (m^2-1)(n^2-1)=(4k^2-1)4k(k+1)
2|k(k+1) 8|4k(k+1)