[ 37 ] 



it It z 



I. When « is even the cofine of na = + i + nc + n.n — 2 * 



c 



2 2 2 2 2 V 



n.n — 2. n — 4 - to"*-^^™* 



I. 2 1.2.3.4 



22 2 



n.n — 2. 



-f- &c. and tlie general term is + 



I.- 2. 3 - - u 



f where !> is always even. When n is of the form 2/, {p being 



any od/l;/ number the fign will be + or — according as — is odd or 

 even and when n is of the form 4^, (^ being any number) it 



V 



will be + or — according as — is even or odd. 



2 23 



2. When n is odd., the cofine of«a = + «f + «. « i c _ &c. 



I. 2. 3 



2 22 ^+ r 

 n. n — I. K. — 3 - to terms -o 



and the general term is -\ — r 



^ — I. 2. S.-i; 



where v is always odd. When n is of the form 4^ + \ the fign 



f + I . 

 will be + or — according as is odd or even, when of the 



V -{■ 1 

 form 4/) + 3 it will be + or — according as is even or odd.. 



Each feries is to be continued till the coefficient becomes = 0. 

 D£M. The general term of the cofine of na„ 



= 4> 



