设正项等比数列{an}公比为q(q>0)
由a3^2=9 a2a6 =>(a3)^2=9(a3/q)*(a3*q^3)
=>(a3)^2=9(a3)^2*q^2
=> q=1/3
又2a1+ 3a2=1 =>2a1+3a1*q=1=>a1=1/3
通项公式an=a1*q^(n-1）=(1/3)^n