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若数列{an}满足a1=5,an+1=(n∈N+),则其{an}的前10项和为
A.50
B.100
C.150
D.200
数列{an}满足递推式an=3an-1+3n-1(n≥2),且a1=5.
(Ⅰ)求a2,a3的值;
(Ⅱ)若存在实数λ使为等差数列,求λ的值及{an}的通项公式;
(Ⅲ)求{an}的前n项和Sn.
已知数列{an}满足an=an-1-an-2(n≥3,n∈N*),它的前n项和为Sn.若S9=6,S10=5,则a1的值为 .
若数列{an}满足a1=5,an+1=+(n∈N+),则其{an}的前10项和为