) 73 C 



■<«• 



§. 29. Quanquam ipfae rationcs, quibus hae pro- 

 prietates innituntiir, nullum plane dubium relinquunt: ta- 

 men haud inutile erit, iftam veritatem etiam pro cafu 

 X— 2 oflendifle, fiue reuera efle 



- i^- 2^ + 5' + 7^_ 12' _ 15^4-22^ + etc. = 0. 



Difcerpatur enim liaec feries itidem in duas, quae fint 

 mutatis fignis: 



/=:-}- I'- 5' -H 12^- 22^-4- 35^- 51- >l- etc. 



? = 2* - 7^ -H 15^ _ 26^ 4- 40^ - 57' _f- etc. 



ac pro prioris fumma inuenienda inftituatur fequens operatio: 



Series i, 25, 144., 484, 1225, 2601, 4900 

 DifF. I. 24, 119, 340, 741, 1376, 2299 



Dilf. II. $5^ 221, 401, 635, 923 



DifF. III. J2€, 180, 234, 288 



Diff. IV. 54, 54, 54 



Diff. V. 



Hinc igitur erit 



. — > 2+ j_ 95 III 



•• 2 4 ~ g 15 



Simili modo pro altera ferie 



Series 4, 49, 225, 675, i(Joo, 3249, 5929 

 Diff. I. 4.5 175, 451, 924, 1649, 26S0 



I^iff. n. 131, 275, 473, 725, 1031 



Diff. III. 144 198, 252, 30<S 



Diff. IV. 54, 54, 54- 



DifF. V. c, o 



Acia Acad, Imp. Sc. Tom. IV. P. /. K Hinc 



