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A221397 as a simple table

na(n)
10
26
330
4144
5672
63108
714328
865976
9303672
101397520
116431136
1229594352
13136184256
14626677152
152883768672
1613270180608
1761065117312
18281002082880
191293081432192
205950345861248
2127381582408576
22126001256419584

[0,6,30,144,672,3108,14328,65976,303672,1397520,
 6431136,29594352,136184256,626677152,2883768672,
 13270180608,61065117312,281002082880,
 1293081432192,5950345861248,27381582408576,
 126001256419584]