# A165311 (b-file synthesized from sequence entry)
0 1
1 4
2 20
3 116
4 724
5 4660
6 30356
7 198644
8 1302100
9 8540596
10 56031764
11 367636340
12 2412218836
13 15827788084
14 103854591380
15 681446713076
16 4471346955604
17 29338975191220
18 192509225431316
19 1263159425822324
20 8288287225499860