an = Sn-S(n-1)
= 2n^2-3n+6-[2(n-1)^2-3(n-1)+6]
= 2n^2-3n+6-[2n^2-4n+2-3n-3+6]
= 4n+1
当n=1时
s1=a1=5
所以数列通项公式为：
4n+1