356 



74 



.1 = n— l 



35. I (32"-l)ß„+^(-l) Q^^S^« '^ßn^, = (_i)n-i(3n_i). 



3C. 2 (32"--l)ß„+^(-l)'(^j]32«-=^'2^»ß„_., = (-l)"-'(3n-2)22"-i. 



s = 1 \ " / 



s =_n— 1 



•27. |(32"-l)ß„+^(-l).(2nJ32„-2.,42.ß^^_^ _ (_1),, >((3n-4)42n-' 4-6n). 



s = 1 

 s = n— 1 



38. I (32n-l)ß„4- V'(— l)s/^M32n-^s52sß„_s= (— 1)" ^ i((3n— 5)52"-i +6n ■ 2^" '). 



S = 1 



S = I 



s = 11 -i 



30. ((32"-|-3)(22n-i+l)~6)ß„ -ryji—ir{l"W"-^5^Bn-s = (-1)"-' (6/1- -5) 52" '• 



s = 1 ^ 



s = n— 1 



31. ((32" + 3)(22''-H-l)-6)ß„+^^(--l)»(^n\62"-2.72»ß^_^ _ 



s= 1 



= (— l)"->((6n— 7)72"-< + 12n). 



s = n— l 

 33. ((32n4-3)(22n-l+l)-6)ß„+^(-l)»Q^)62«-2sll2sß„_^ = 



= (— l)''i((6/i— 11)112" ' + 12n- 52"-'). 



s= 1 



2. Formules contenant les r„. 

 »33. X^-l)^(2'">"-» = £n + (-l)"-. 



s=0 

 s = n - 1 



*34. ^(-1)'(^"27^)^"- = (-1)"-'- 



s = 

 s = n— 1 



s — 



s = n— 1 



*36. r,.+, -^(-1)^(25+2)^«- = ^"- 



s = u 



*37. ^(-1)^(25+1)2''^"- = (-1)" '22" 1. 



s = n— 1 



