设数列{an}满足an=2an-1+n 若{an}是等差数列,求{an}通项公式

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/05 11:55:53

设数列{an}满足an=2an-1+n 若{an}是等差数列,求{an}通项公式
设数列{an}满足an=2an-1+n 若{an}是等差数列,求{an}通项公式

设数列{an}满足an=2an-1+n 若{an}是等差数列,求{an}通项公式
∵{an}是等差数列 ∴an=a1+(n-1)d
∵an=2an﹣1+n ∴a1+(n-1)d=2a1+2(n-2)d+n
∴a1+(n-3)d+n=0 ∴an﹣2=﹣n
∴an=﹣(n+2)

设数列{an}满足an=2an-1+n 若{an}是等差数列,求{an}通项公式 数列{an}满足a1=1 an+1=2n+1an/an+2n 设数列{an}满足lg(1+a1+a2+...+an)=n+1,求通项公式an 设数列{an}满足a1=2,an+1=an+1/an(n=1,2,3.),证明:an>根号下(2n+1).急用 数列{an}满足a1=1,且an=an-1+3n-2,求an 已知数列{an}满足an+1=2an+3.5^n,a1=6.求an 数列{An}满足a1=1/2,a1+a2+..+an=n方an,求an 设b>0,数列an满足a1=b,an=nban-1/an-1+n-1(n≥2)求数列an通向公式. 设b>0,数列an满足a1=b,an=nban-1/an-1+n-1(n≥2)求数列an通向公式 已知数列An满足An>0,其前n项和为Sn为满足2Sn=An的平方+An(1)求An(2)设数列Bn满足An/2的n次方,Tn=b1+b2+ 设数列AN满足A1等于1,3(A1+a2+~+AN)=(n+2)an,求通向公式 设数列{an}中,a1=2,an+1=an+n+1,则通项an=? 设数列{an}中,若an+1 =an+ an+2 (n∈N*),则称数列{an}为“凸数列” .设数列{an}为“凸数列”求第二问证明设数列{an}中,若an+1 =an+ an+2 (n∈N*),则称数列{an}为“凸数列” .设数列{an}为“凸数列”,若a1 =1, 设数列an满足a1=2,a(n+1)=3an+2^(n-1),求an2,设数列an满足a1=2,a(n+1)=3an+2n,求an 数列{an}满足a1=3/2,an+1=an2-an+1,求证:1/an=1/(an)-1 - 1/(an+1)-1数列{an}满足a1=3/2,an+1=an2-an+1,求证:1/an=1/(an)-1 - 1/(an+1)-1设Sn=1/a1+1/a2+...+1/an,n>2证明1 已知数列{an}满足:a1=3,an+1=(3an-2)/an ,n∈N*.(Ⅰ)证明数列{(an-1)/an-2已知数列{an}满足:a1=3,an+1=(3an-2)/an ,n∈N*.(1)证明数列{(an-1)/an-2 }为等比数列,并求数列{an}的通项公式;(2)设设b 已知数列{an}满足a1=-1,an=[(3n+3)an+4n+6]/n,bn=3^(n-1)/an+2.求数列an的通向公式.设数列bn是的前n项和已知数列{an}满足a1=-1,an=[(3n+3)an+4n+6]/n,bn=3^(n-1)/an+2.(1)求数列an的通向公式.(2)设数列bn是的前n项和为sn, 已知以1为首项数列{an}满足: an +1(n为奇数) an+1={an/2(n为偶数)}设数列{an}前n项和为sn,求数列{sn}前n项和Tn