若数列{an}满足a1+3a2+3²a3+···+3^n-1an=n/2 则an=

若数列｛an｝满足a1,a2-a1,a3-a2,...是以1为首相,3为公比的等比数列,则an______ 若数列an满足,a1+a2+a3+.+an=3n-2求 an的通项公式 若数列｛an｝满足：a1=1,an+1=2an,n=1,2,3….则a1+a2+…+an=______. 若数列｛an｝满足a1=1,an+1=2an,n=1,2,3,……,则a1+a2+……+an=____________ 若数列{an}满足a1+2a2+3a3+~~+nan=n(n+1)(2n+1),则an= 设数列AN满足A1等于1,3(A1+a2+~+AN)=(n+2)an,求通向公式 已知数列{an}满足a1=1,a2=3,an+2=3an+1-2an求an 若数列{an}满足a1×a2×a3…an=n²+3n+2,求数列{an}的通项公式 已知数列｛an｝的前n项和为Sn 1若数列｛an｝是等比数列,满足2a1+a3=3a2.a3+2是a已知数列｛an｝的前n项和为Sn1若数列｛an｝是等比数列,满足2a1+a3=3a2.a3+2是a2.a4的等差中项,求数列｛an｝的通向公式 数列{an}满足a1=3,a2=6,an+2=an+1-an,求a2013 数列{an}满足a1=3,a2=6,an+2=an+1-an,求a2008 已知数列an满足a1=1,a2=3,an+1.an-1=an,求a2013 数列{an}满足:a1,a2-a1,a3-a2……,an-an-1构成以2为首项,3为公比的等比数列,求an 已知数列{an}满足a1,a2-a1,a3-a2,...,an-an-1,...是首项为1,公比为1/3的等比数列.求an的表达式? 数列an满足a1=1,a2=1/3,并且an(an-1+an+1)=2an+1an-1.则数列第2012项为? 数列{an}{bn}满足bn=a1+2a2+3a3+…+nan/(1+2+3+…+n),若数列{an}为等差数列,求证；{bn}为等差数列. 数列an满足,a1=1/4,a2=3/4,an+1=2an-an-1(n≥2,n属于N*),数列bn满足b1 在数列｛an｝中,若a1+a2+.+an=2^n,则(a1)^3+(a2)^3+(an)^3等于______