A170589-OEIS公司

A170589号作为一个简单的表

n个	a（n）
0	1
1	4
2	12
三	36
4	108
5	324
6	972
7	2916
8	8748
9	26244
10	78732
11	236196
12	708588
13	2125764
14	6377292
15	19131876
16	57395628
17	172186884
18	516560652
19	1549681956
20	4649045868
21	13947137604
22	41841412812
23	125524238436
24	376572715308
25	1129718145924

[1,4,12,36,108,324,972,2916,8748,26244,78732,236196,708588,2125764,6377292,19131876,57395628,172186884,516560652,1549681956,4649045868,13947137604,41841412812,125524238436,376572715308,1129718145924]