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A026651 as a simple table

na(n)
21
39
440
5240
6915
75103
818704
9101952
10368490
111990890
127154928
1338514528
14138086403
15742202055
162658662560
1714283407616
1851156225342
19274842096462
20984532674800
215291030979360
2218960255044654
23101937273452454
24365451691152864

[1,9,40,240,915,5103,18704,101952,368490,1990890,
 7154928,38514528,138086403,742202055,2658662560,
 14283407616,51156225342,274842096462,984532674800,
 5291030979360,18960255044654,101937273452454,
 365451691152864]