77 359 



î= ni 



66. 



6- = n 1 



67 



.5= 1 



6 = 71 1 



s = U 



s = n- 1 



68. ^(-1)^(25^"- 1)3^+' fin-. = -r„+i-(-l)"22"+'. 



s =^ 



Å -^ ft - 1 



69. {2n-\-l)En-r^(-lY(^^'}^^)é-'^En-s = ^=^^(32"-3). 



70. ^("l)'(2"+2) ^""^-^ = ^^)-""\32"+> -3). 



s = n 1 



S = U 



s = n 1 



72. ^(-l)'(2s"+i)5''+'£«-.s = T„+, + (-l)" '(.22"-3)22«+<. 



s = 

 A = n- 1 



73. ^(-l)»->(2"Zl)3^"--'£n-.s = ^"^^„ + (-1)«. 



S= I 



S = ft - 1 



74. ^(-l)^~'(^^l})32«--^52-l£„., = ^"l-3lr„ + (_l)n(52n-l_22«). 



s = l 

 5 =_n- I 



75. ^(-l)-i(^^l})32«-2»72»-iÊ„_, = _^!!!^r„ + (-l)"(72" i-24"-i). 



4. Exemples des formules irrégulières. 

 1) /4n — 2s + l\ o (— l)"-'n(n+l) 



V (-l)'(2n +l) /4n 2s + l\^ 

 ^ (4n-2s+l)2''4 2s + l ^ «" » - 24''-2 



s = n— 1 



^ 4n-2s-l l 2s + l yl ^«-^ - ^ ^ ^> • 



S = U 



s = n— 1 



V (-l)M2n- l) /4n-2s-2\^ _ (-1)"^ 

 ^ (2n — s— 1)22^ 2s ^n-s - 22„-2 



s = u 



79 'y ' i-^y" (in--2s\p _ l-(-l)» 

 ^ (2n-s)22»i 2s ;^"-» - 



02n 



