问题
单项选择题
若数列{an}由a1=2,an+1=an+2n(n≥1)确定,则a100的值是( )。
A.9900
B.9902
C.9904
D.10100
E.11000
答案
参考答案:B
解析:
[分析]: 由题知a100=a99+2×99
=a98+2×98+2×99
=a97+2×97+2×98+2×99
┇
=a1+2×1-(2×2+…+2×99
=2+2(1+2+3+…+99)
=9902