有一分数序列2/1,3/2,5/3,8/5,.求出这个序列的前20的和 请发到shamanman19

dim a,b,i as integer
dim s as single
a=1
b=2
s=0
for i=1 to 10
s=s+b/a
a=a+b
s=s+a/b
b=a+b
next i
print s