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A069143 as a simple table

n a(n)
1 1
2 1
3 3
4 7
5 18
6 31
7 57
8 180
9 320
10 1092
11 2478
12 10368
13 25704
14 100800
15 393120
16 1965600
17 10326624
18 39657600
19 131580288
20 511223790
21 1469266560
22 4911616440
23 22120488000
24 95841111600
25 460020244320
26 2163425531904
27 9805180170240

[1,1,3,7,18,31,57,180,320,1092,2478,10368,25704,
 100800,393120,1965600,10326624,39657600,131580288,
 511223790,1469266560,4911616440,22120488000,
 95841111600,460020244320,2163425531904,
 9805180170240]

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Last modified December 5 10:11 EST 2021. Contains 349543 sequences. (Running on oeis4.)