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A001801 as a simple table

na(n)
03
115
2105
3315
46930
518018
690090
7218790
82078505
94849845
1022309287
1150702925
121825305300
134071834900
1418032411700
1539671305740
16347123925225
17755505013725
183273855059475
197064634602025
20121511715154830

[3,15,105,315,6930,18018,90090,218790,2078505,
 4849845,22309287,50702925,1825305300,4071834900,
 18032411700,39671305740,347123925225,755505013725,
 3273855059475,7064634602025,121511715154830]