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A051906 as a simple table

na(n)
11
20
30
40
510
60
728
80
90
100
1188
120
134524
140
150
160
17140692
180
19820496
200
210
220
23128850048
240
251957725000
260
270
280
29605917055356
300
3113404947681712
320
330
340

[1,0,0,0,10,0,28,0,0,0,88,0,4524,0,0,0,140692,0,
 820496,0,0,0,128850048,0,1957725000,0,0,0,
 605917055356,0,13404947681712,0,0,0]