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A031882 as a simple table

na(n)
11
23
37
49
533
699
7111
8777
99999
1033333
1155555
12111111
13777777
147777777
1555555555

[1,3,7,9,33,99,111,777,9999,33333,55555,111111,
 777777,7777777,55555555]