1,3,4,13,53,()
A.267
B.531
C.690
D.891
:1/3, 1, 1, 13/17, 17/33, () A.21/34 B.21/65 C.17/53 D.1
3,4,13,53,()。 A.213 B.425 C.690 D.710
3,4,13,53,()。 A.213B.425C.690D.710
2,4,3,(),13/4,27/8,53/16。A.1 B.7/2 C.7/3 D.4
1,3,4,13,53,()A.267B.531 C.690D.891
1,3,4,13,53,()A.267B.531C.690 D.891