(2017·洛阳市统考)已知数列{an}的前n项和为Sn,an≠0,a1=1,且2anan+1=4Sn-3(n∈N*).
(1)求a2的值并证明:an+2-an=2;
(2)求数列{an}的通项公式.
数列,,,,…的通项公式an为( )