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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”).

A197593 as a simple table

na(n)
11
21
34
418
598
61460
735691
81385653
9113578137
1017175107452
114747357788947
122462207136693903

[1,1,4,18,98,1460,35691,1385653,113578137,
 17175107452,4747357788947,2462207136693903]