2 3 1 2 1 3

then the two 1's enclose 1 other digit, the two 2's enclose 2 other digits, and the two 3's enclose 3 other digits.

Can you find a similar arrangement using the seven pairs 1,1,...7,7?

I just get up to 4.. i will try to find again... i very curious if there is a RULE of this number's...

thanks for give me another FUNNY number's