急!数列求和：Sn=（2n-1）除以2的n-1次方

Tn=s1+s2+s3+…sn
求Tn

---

sn=(2n-1)/2^(n-1)
s(n-1)=(2n-3)/2^(n-2)
sn-s(n-1)=(2n-1)/2^(n-1)-(2n-3)/蠢弊2^(n-2)
an=(2n-1)/慧档毁2^(n-1)-(2n-3)/2^(n-2)
an=(2n-1)/前备2^(n-1)-2*(2n-3)/2^(n-1)
an=[(2n-1)-2*(2n-3)]/2^(n-1)
an=[2n-1-4n+6]/2^(n-1)
an=(5-2n)/2^(n-1)

---

详团毁改余局见图塌判片

---