# A004386 (b-file synthesized from sequence entry)
5 1
6 48
7 1540
8 41664
9 1028790
10 24040016
11 541931236
12 11919192480
13 257575523205
14 5494563394320
15 116068178638776
16 2433440563030400
17 50718300243156000
18 1052134368066259632
19 21743950029947469800