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A147216 as a simple table

na(n)
11
21
31
41
55
621
761
8299
91693
1011273
1184165
12889613
1311762051
14208288599
154127254537
16109970171123

[1,1,1,1,5,21,61,299,1693,11273,84165,889613,
 11762051,208288599,4127254537,109970171123]