# A218873 (b-file synthesized from sequence entry)
1 1
2 1
3 2
4 3
5 20
6 168
7 25740
8 1627920
9 7600186994400
10 91351145008363640400
11 41220780807793167133364240240011200
12 86885947737342403570395603462501113422055643279216000