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若数列{an}满足a1=2且an+an-1=2n+2n-1,Sn为数列{an}的前n项和,则log2(S2 012+2)=________.
若数列{an}满足a1=,an=1-,n≥2,n∈N*,则a2003等于 ( )
A. B.-1 C.2 D.1
若数列{an}满足an+1=an+an+2(n∈N*),则称数列{an}为“凸数列”.(1)设数列{an}为“凸数列”,若a1=1,a2=-2,试写出该数列的前6项,并求出前6项之和;(2)在“凸数列”{an}中,求证:an+3=-an,n∈N*;(3)设a1=a,a2=b,若数列{an}为“凸数列”,求数列前2011项和S2011.