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Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A146176 as a simple table

na(n)
11
21
31
41
51
61
71
81
91
101
113
123
1313
1413
1531
1631
1779
1879
19513
20513
214397
224397
2330071
2430071

[1,1,1,1,1,1,1,1,1,1,3,3,13,13,31,31,79,79,513,
 513,4397,4397,30071,30071]