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A281781 as a simple table

na(n)
01
11
2-1
32
4-1
5-2
66
7-6
83
9-1
10-1
119
12-18
1323
14-27
1523
16-1
17-24
1849
19-89
20121
21-117
2296
23-60
24-18
25138
26-275
27408
28-525
29592
30-566
31444
32-181
33-276
34854
35-1485
362154
37-2765
383157
39-3131
402571
41-1468
42-301
432813
44-5860
459153
46-12386
4715082
48-16664
4916558
50-14125

[1,1,-1,2,-1,-2,6,-6,3,-1,-1,9,-18,23,-27,23,-1,
 -24,49,-89,121,-117,96,-60,-18,138,-275,408,-525,
 592,-566,444,-181,-276,854,-1485,2154,-2765,3157,
 -3131,2571,-1468,-301,2813,-5860,9153,-12386,
 15082,-16664,16558,-14125]