|
|
评论
|
数字从右边开始计数，因此d_1（n）是一位数，d_2（n）则是十位数，以此类推。
di（n）可以使用以下任一公式求得：
*di（n）=楼层（n）/10^（i-1））mod 10；
*di（n）=楼层（n/10^（i-1））-10*楼层（n/10^i）。
对于n<1000，该序列可以写成一系列10 X 10子表：
子表1：
0, 2, 4, 6, 8, 10, 12, 14, 16, 18
3, 5, 7, 9, 11, 13, 15, 17, 19, 21
6, 8, 10, 12, 14, 16, 18, 20, 22, 24
9, 11, 13, 15, 17, 19, 21, 23, 25, 27
12, 14, 16, 18, 20, 22, 24, 26, 28, 30
15, 17, 19, 21, 23, 25, 27, 29, 31, 33
18, 20, 22, 24, 26, 28, 30, 32, 34, 36
21, 23, 25, 27, 29, 31, 33, 35, 37, 39
24, 26, 28, 30, 32, 34, 36, 38, 40, 42
27, 29, 31, 33, 35, 37, 39, 41, 43, 45
子表2：
5, 7, 9, 11, 13, 15, 17, 19, 21, 23
8, 10, 12, 14, 16, 18, 20, 22, 24, 26
11, 13, 15, 17, 19, 21, 23, 25, 27, 29
14, 16, 18, 20, 22, 24, 26, 28, 30, 32
17, 19, 21, 23, 25, 27, 29, 31, 33, 35
20, 22, 24, 26, 28, 30, 32, 34, 36, 38
23, 25, 27, 29, 31, 33, 35, 37, 39, 41
26, 28, 30, 32, 34, 36, 38, 40, 42, 44
29, 31, 33, 35, 37, 39, 41, 43, 45, 47
32, 34, 36, 38, 40, 42, 44, 46, 48, 50
子表3：
10, 12, 14, 16, 18, 20, 22, 24, 26, 28
13, 15, 17, 19, 21, 23, 25, 27, 29, 31
16, 18, 20, 22, 24, 26, 28, 30, 32, 34
19, 21, 23, 25, 27, 29, 31, 33, 35, 37
22, 24, 26, 28, 30, 32, 34, 36, 38, 40
25, 27, 29, 31, 33, 35, 37, 39, 41, 43
28, 30, 32, 34, 36, 38, 40, 42, 44, 46
31, 33, 35, 37, 39, 41, 43, 45, 47, 49
34, 36, 38, 40, 42, 44, 46, 48, 50, 52
37, 39, 41, 43, 45, 47, 49, 51, 53, 55
...
每个子表为10 X 10。设T_n（j，k）=子表n第k列第j行中的元素。T_n（1,1）=5*（n-1）。T_n（j，1）=5*（n-1）+3*（j-1）。T_n（1，k）=5*（n-1）+2*（k-1）。总的来说，T_n（j，k）=5*（n-1）+3*（j-1）+2*（k-1）=5*n+3*j+2*k-10。
（完）
|
