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A271681 as a simple table

na(n)
11
26
360
41939
5139023
625765212
711078521995
811498758930720
928198545925392908
10165452583814243981520

[1,6,60,1939,139023,25765212,11078521995,
 11498758930720,28198545925392908,
 165452583814243981520]