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A290030 as a simple table

na(n)
01
1-1
23
3-1
415
5-3
663
7-9
8135
9-15
1099
11-9
1212285
13-945
14405
15-27
166885
17-405
18161595
19-8505
201403325
21-66825
22419175
23-18225
2424877125
25-995085
26229635
27-8505
28528525
29-18225
3026101845
31-841995
32214708725
33-6506325
341148175
35-32805
3631479513975
37-850797675

[1,-1,3,-1,15,-3,63,-9,135,-15,99,-9,12285,-945,
 405,-27,6885,-405,161595,-8505,1403325,-66825,
 419175,-18225,24877125,-995085,229635,-8505,
 528525,-18225,26101845,-841995,214708725,-6506325,
 1148175,-32805,31479513975,-850797675]