1+2+3+5+8+13+21+34.+233=
1个回答

F(n+2)-F(n+1)=F(n)

F(n+1)-F(n)=F(n-1)

.

F(3)-F(2)=F(1)

全加上

F(1)+F(2)+F(3)+.F(n)=F(n+2)-F(2)=

=F(n)+F(n+1)-F(2)

=233+377-2

=608