# A134988 (b-file synthesized from sequence entry)
2 1
3 0
4 1
5 4
6 22
7 144
8 1089
9 9308
10 88562
11 927584
12 10603178
13 131368648
14 1753970380
15 25112732512
16 383925637137
17 6243618722124
18 107644162715098
19 1961478594977856
20 37671587406585006
21 760654555198989240
22 16110333600696417780
23 357148428086308848480
24 8271374327887650503130