# A074032 (b-file synthesized from sequence entry)
1 0
2 0
3 1
4 4
5 12
6 40
7 144
8 512
9 1813
10 6528
11 23808
12 87380
13 322560
14 1198080
15 4473647
16 16777216
17 63160320
18 238605640
19 904200192
20 3435973836
21 13089411609
22 49977753600
23 191219367936
24 733007751680
25 2814749599332
26 10825959997440
27 41699995927744
28 160842843834660