# A172393 (b-file synthesized from sequence entry)
0 1
1 4
2 -2
3 8
4 -20
5 96
6 -324
7 1648
8 -6348
9 33200
10 -137848
11 732640
12 -3193296
13 17148608
14 -77335400
15 418289696
16 -1934677436
17 10518803376
18 -49611450120
19 270796872160
20 -1297234193744
21 7102371571840
22 -34458382484976
23 189117499963840