# A274448 (b-file synthesized from sequence entry)
0 1
1 2
2 16
3 192
4 3072
5 61440
6 1474560
7 41287680
8 1321205760
9 47563407360
10 1902536294400
11 83711596953600
12 4018156653772800
13 208944145996185600
14 11700872175786393600
15 702052330547183616000
16 44931349155019751424000
17 235025518657026392064000
18 219983885462976702971904000
19 16718775295186229425864704000
20 1337502023614898354069176320000