here,
for first series, coefficient of x^n
tn+1 = rCn
i.e. tn+1 = [r(r-1)(r-2) .... (r-n+1)] / n! (coefficient)
now, (1/1-x)r
=> (1-x)-r
The binomial expansion becomes,
=> 1+(-r)(-x) + [(-r-1)(-x)2]/2! + .....
Thus, coeffecient of xn is
=> tn+1 = [r(r-1)(r-2) .... (r-n+1)] / n! (coefficient)
Thus in both cases the coefficients are the same ..