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The seventh grade explores conventional application problems.
A classmate created some circles in the following arrangement on the computer.

●○●●○●●●○●●●●○●●●●●○●●●●●●○

If a series of circles are continuously derived from the above set of circles according to this law, how many hollow circles are there in the first circle in 2005?

1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,/.

2, 6, 8,14, 22, 36, 58, 94,152, 246, 398, 644,1042,1686, 2728 ... What's behind 2728?

Square of 3-square of 65438+0 = 8 *1; Square of 5-square of 3 = 8 * 2; Square of 7-square of 5 = 8 * 2;

9 squared -7 squared = 8 * 4( 1)A squared -B squared =96, then A= B=

The formula with n represents the above law.

Write an equation in which the square difference between two consecutive odd numbers is 888.

Found 1+3, 1+3+5, 1+3+5+7, 1+3+5+7+9, ...,1+3+7+9. ...