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A031231 as a simple table

na(n)
11
21
31
41
52
61
72
83
94
104
115
125
136
146
156
165
175
186
196
206
216
226
236
246
256
265
275
286
296
306
316
326
336
346
356
365
375
386
396
406
416
426
436
446
457
466
475
486
495
506
517
526
536
547
556
566
577
586
596
607
618
627
638
649
6510
6611
6712
6812
6913
7014
7114
7215
7316
7416
7517
7617
7716
7817
7917
8018
8119
8219

[1,1,1,1,2,1,2,3,4,4,5,5,6,6,6,5,5,6,6,6,6,6,6,6,
 6,5,5,6,6,6,6,6,6,6,6,5,5,6,6,6,6,6,6,6,7,6,5,6,5,
 6,7,6,6,7,6,6,7,6,6,7,8,7,8,9,10,11,12,12,13,14,
 14,15,16,16,17,17,16,17,17,18,19,19]