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A161920 as a simple table

na(n)
11
22
34
43
56
65
76
84
98
107
118
126
139
147
158
165
1710
189
1910
208
2111
229
2310
247
2512
2610
2711
288
2912
309
3110
326
3312
3411
3512
3610
3713
3811
3912
409
4114
4212
4313
4410
4514
4611
4712
488
4915
5013
5114
5211
5315
5412
5513
569
5716
5813
5914
6010
6115
6211
6312
647
6514
6613
6714
6812
6915
7013
7114
7211
7316
7414
7515
7612
7716

[1,2,4,3,6,5,6,4,8,7,8,6,9,7,8,5,10,9,10,8,11,9,
 10,7,12,10,11,8,12,9,10,6,12,11,12,10,13,11,12,9,
 14,12,13,10,14,11,12,8,15,13,14,11,15,12,13,9,16,
 13,14,10,15,11,12,7,14,13,14,12,15,13,14,11,16,14,
 15,12,16]