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A271180 as a simple table

na(n)
01
11
25
315
445
5125
6342
7921
82461
96535
1017282
1145567
12119898
13315020
14826830
152168583
165684731
1714896459
1839024899
19102216045
20267693813
21700997144
221835543565
234806092673
2412583591525
2532946281848
2686258240735
27225834015840

[1,1,5,15,45,125,342,921,2461,6535,17282,45567,
 119898,315020,826830,2168583,5684731,14896459,
 39024899,102216045,267693813,700997144,1835543565,
 4806092673,12583591525,32946281848,86258240735,
 225834015840]