有序列如下:
n = 0: X
n = 1: Y
n = 2: YX
n = 3: YXY
n = 4: YXYYX
n = 5: YXYYXYXY
n = 6: YXYYXYXYYXYYX
n = 7: YXYYXYXYYXYYXYXYYXYXY
n = 8: YXYYXYXYYXYYXYXYYXYXYYXYYXYXYYXYYX
n = 9: YXYYXYXYYXYYXYXYYXYXYYXYYXYXYYXYYXYXYYXYXYYXYYXYXYYXYXY
... ...
當 n 趨於無窮,Y數量和X數量的比值是多少 :-)
另外玲蘭過獎。實不能和龍叔相比,種菜除外 :-)