数列{an}满足a1=1,当n大于等于2时,an=an-1+n,则a10=多少?

问题描述:

数列{an}满足a1=1,当n大于等于2时,an=an-1+n,则a10=多少?

a10=a9+10=a8+9+10=……=1+2+3+4+5+6+7+8+9+10=55