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Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A331850 as a simple table

na(n)
11
22
34
49
518
654
7120
8324
9900
102406
116400
1219600
1350176
14148042
15442325
161373070
173954113

[1,2,4,9,18,54,120,324,900,2406,6400,19600,50176,
 148042,442325,1373070,3954113]