回复：证明题一

By induction on k, one can show that 69444...445555...5556=(83...34)^2, where there are k+1 consecutive 3's. The key point is to note that if
denote 83....34 by x_k, then x_{k+1}=(x_k -1)*10+4=10 x_k -6.

所有跟帖： 

• 是这么个理儿吧 -冻凉之才- ♂ (0 bytes) () 02/06/2007 postreply 16:51:11

• 没看明白，或者说过程不完整。。。 -黑巧克力- ♂ (0 bytes) () 02/07/2007 postreply 01:25:21

• 以下是我的证明 -黑巧克力- ♂ (1022 bytes) () 02/07/2007 postreply 02:09:53

• This is great! -冻凉之才- ♂ (0 bytes) () 02/07/2007 postreply 07:36:13

• 看着都晕，敬佩下得了 -丑女郎- ♀ (0 bytes) () 02/07/2007 postreply 10:06:48