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A166668 as a simple table

na(n)
11
221
331
4441
551
6651
771
89261
9961
101071
11111
1213671
13131
141491
151581
16194481
17171
1820181
19191
2022491
212201
222331
23231
24287091
252601
262751
2729791
2831311
29291
3033201
31311
324084101
333441
343591
353621
36423801
37371
384011
394061
40472311
41411
4246221
43431

[1,21,31,441,51,651,71,9261,961,1071,111,13671,
 131,1491,1581,194481,171,20181,191,22491,2201,
 2331,231,287091,2601,2751,29791,31311,291,33201,
 311,4084101,3441,3591,3621,423801,371,4011,4061,
 472311,411,46221,431]