# A177285 (b-file synthesized from sequence entry)
0 1
1 1
2 6
3 90
4 2520
5 113400
6 3356640
7 75336660
8 1500131820
9 29660400822
10 620330067782
11 13125403608162
12 274194614811528
13 5605288189594200
14 112437639146871360
15 2235073249396108440
16 44209749453949113840
17 870798759948756386976
18 17069437222534487122608
19 332789644153015982087550
20 6455422726721469064982952