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A057771 as a simple table

na(n)
00
11
21
31
42
56
6109
723746
8106228849
99365022303540
1020890436195945769617
111478157455158044452849321016

[0,1,1,1,2,6,109,23746,106228849,9365022303540,
 20890436195945769617,1478157455158044452849321016]