# A024335 (b-file synthesized from sequence entry)
0 0
1 0
2 1
3 -3
4 11
5 -50
6 334
7 -3024
8 32388
9 -381744
10 4838076
11 -65583540
12 950021940
13 -14693894280
14 242272566600
15 -4248337358160
16 79009205066400
17 -1553851954502400
18 32222584311078480
19 -702651673196884080
20 16071124886746959600
21 -384653713958912916000