a1=2/3,an=-2/3,n=14.求等差数列{an}的Sn

数列｛an},a1=1,an+1=2an-n^2+3n,求｛an｝. 数列an满足a1=1/3,Sn=n(2n-1)an,求an 数列{an},a1=3,an*a(n+1)=(1/2)^n,求an 已知数列｛an｝中,a(n+1)=an+2^n,a1=3,求an 在数列an中,a1=2 an+1=an+3n则an= 数列｛an｝满足a1=1,且an=an-1+3n-2,求an 已知{an}满足a1=1.an=3*n+2An-1,求an an+1 ,n+1是下表 ,an+1=an^3 a1=2 ,求an 已知a1=2 a(n+1)=2an+2^n+3^n 求an 1.a1=3 且 a（n+1）=an+5ana（n+1）2.a1=1 且 a（n+1）=an+2n+13.a1=1 且 a（n+1）=an+1/4n^2-14.a1=1 an=n+1/n*a（n+1）求各题的an a1=2/3,an=-2/3,n=14.求等差数列{an}的Sn 数列a1=-1,an+1=2an+4*{3}^{n-1}a1=-1,an+1=2an+4*{3}^{n-1},求an 2an+a(n-1)=3,a1=2 一道数学题、、数列{an}：a1=4,an=3an-1+2n-1,n≥2求an. 数列{an}满足a1=1,an=3n+2an-1(n≥2)求an 数列an.a1=1,a1+2a2+3a3+.+nan=(n+1)/2*an+1求an 在数列｛an｝中,若a1+a2+.+an=2^n,则(a1)^3+(a2)^3+(an)^3等于______ 设数列AN满足A1等于1,3(A1+a2+~+AN)=(n+2)an,求通向公式