Page 130 - Numbertheory

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: 24 :( )
.2, 3, 5, 7, 11, 13, 17, 19, 23

24 = 5 +19 = 7 +17 = 11+13

.3

26 −1 ( ) 25 −1 ( ) [British IMC 2006] ( )
23 −1 ( ) 22 −1 ( )

: :( ) ()

22 −1 = 3

23 −1 = 7

25 −1 = 31

. 26 −1 = 63 = 7 ×9

[British IMC 1999] ( )

(1+ 1 )(1+ 1) (1+ 1 ) ... (1+ 1 )
234 n

n( ) n ()
. ()
3 n( )

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