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A146668 as a simple table

na(n)
11
21
31
41
51
61
71
81
917
1017
1149
1249
13253
14253
153643
163643
17105629
18105629
192607651
202607651
2196901053
2296901053

[1,1,1,1,1,1,1,1,17,17,49,49,253,253,3643,3643,
 105629,105629,2607651,2607651,96901053,96901053]