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A072280 as a simple table

na(n)
12
21
37
46
541
65
7239
834
9199
1029
118119
1233
1347321
14169
15961
161154
171607521
18197
199369319
201121
2132641
225741
23318281039
241153
2545245801
2633461
277761799
2838081
2963018038201
301345
31367296043199
321331714
3337667521
341136689
351273319041
3639201
3772722761475561

[2,1,7,6,41,5,239,34,199,29,8119,33,47321,169,961,
 1154,1607521,197,9369319,1121,32641,5741,
 318281039,1153,45245801,33461,7761799,38081,
 63018038201,1345,367296043199,1331714,37667521,
 1136689,1273319041,39201,72722761475561]