an=sn-s(n-1)=3n²-2n-3(n-1)²+2(n-1)=3n²-2n-3n²+6n-3+2n-2=6n-5同理a(n+1)=s(n+1)-sn=6n+1a(n+1)-an=6所以{an}为等差数列，公差为6通项公式为an=6n-5首项a1=6-5=1
