# A024297 (b-file synthesized from sequence entry)
0 0
1 1
2 12
3 344
4 18496
5 1617152
6 209249792
7 37538874368
8 8908210487296
9 2699849585000448
10 1017035120794927104
11 466006356701359898624
12 255181639297776949919744
13 164564302025304936925888512