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A257387 as a simple table

na(n)
01
11
22
34
49
521
651
7127
8323
9834
102179
115743
1215238
1340637
14108800
15292200
16786703
172122387
185735596
1915522682
2042064028
21114117541
22309918698
23842489130
242292332265
256242655886

[1,1,2,4,9,21,51,127,323,834,2179,5743,15238,
 40637,108800,292200,786703,2122387,5735596,
 15522682,42064028,114117541,309918698,842489130,
 2292332265,6242655886]