A221579-OEIS公司

A221579号作为一个简单的表

n个	a（n）
0	1
1	9
2	99
三	990
4	9990
5	99891
6	999900
7	9998901
8	99998910
9	999989010
10	9999989010
11	99999889110
12	999999890109
13	9999998890200
14	99999998891100
15	999999988901199
16	9999999988902090
17	99999999888912090
18	999999999889011990
19	9999999998889021990

[1,9,99,990,9990,99891,999900,9998901,99998910,999989010,9999989010,99999889110,999999890109,9999998890200,99999998891100,999999988901199,9999999988902090,99999999888912090,999999999889011990,9999999998889021990]