有穷数列{an}}（n属于N*）满足a1=an,a2=an-1,…,an=a1,即ai=an-i+1（n属于N*且1≤i≤n）.
问题描述：
有穷数列{an}}（n属于N*）满足a1=an,a2=an-1,…,an=a1,即ai=an-i+1（n属于N*且1≤i≤n）.
有穷数列{an}（n属于N*）满足a1=an,a2=an-1,…,an=a1,即ai=an-i+1（n属于N*且1≤i≤n）.若｛an｝的项数为7,且a1,a2,a3,a4成等差数列,a1=2,a4=11,试写出｛an｝的每一项
答
a(1)=a(7)=2,a(2)=a(6),a(3)=a(5),a(4)=11.a(2) = a(1) + d = 2+d,a(3) = a(1) + 2d = 2 + 2d,11 = a(4) = a(1) + 3d = 2 + 3d,d = 3.a(1)=a(7)=2,a(2)=a(6)=2+d=5,a(3)=a(5)=2+2d=8,a(4)=11n不是在【1，7】么，就这么简单？题目中说“{a(n)}的项数为7” 啊。。也许是我想的太复杂了？3Q啦~多谢楼主的及时采纳。。很高兴有机会为楼主效劳~~