# A168921 (b-file synthesized from sequence entry)
0 1
1 4
2 12
3 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 41841412806
23 125524238400
24 376572715152
25 1129718145312