# A170993 (b-file synthesized from sequence entry)
2 2
3 1456
4 91920
5 1931200
6 21639720
7 160786272
8 893985280
9 4001984640
10 15166797900
11 50211875600
12 149342289472
13 404551482816
14 1017967450960
15 2389725895200
16 5320611901440
17 11218821981312
18 22749778149786
19 44125038791280
20 83117833890400
21 150796252355840
22 267599811354744