22 N. F. DUPUIS : CRUCES MATHEMATIC.E. 



Dividiug the equal expressions by-x — y, and making »/ ^ x, we obtain 



,^_., ^ 1 + 3a,.r-'+5a,r'+ (2« + l)ao„+,.i-»" + . . . 



and 



1 



and equating coefficients of x'", 

 and 



wliich gives all the coefficients by giving consecutive powers to n. 



^ ^ - 2rt + 1 



