# A009454 (b-file synthesized from sequence entry)
0 0
1 1
2 -1
3 1
4 0
5 -10
6 90
7 -730
8 6160
9 -55900
10 549900
11 -5864300
12 67610400
13 -839594600
14 11186357000
15 -159300557000
16 2416003824000
17 -38894192662000
18 662595375078000
19 -11911522255750000
20 225382826562400000