# A111600 (b-file synthesized from sequence entry)
10 1
11 110
12 7260
13 377520
14 17177160
15 721440720
16 28857628800
17 1121325004800
18 42890681433600
19 1629845894476800
20 61934143990118400
21 2364758225077248000
22 91043191665474048000
23 3543681152517682176000
24 139722285442125754368000