# A053550 (b-file synthesized from sequence entry)
1 1
2 2
3 -4
4 72
5 -2168
6 114864
7 -10671216
8 1787642272
9 -557621854080
10 332091938264960
11 -383877081387120640
12 870132605833456937472
13 -3891989736269204588784384
14 34485850497928703119235323904
15 -606809291874393995479640098992128