a(n) = A000010(A006862(n)).

Terms

a(0) =1a(1) =2a(2) =6a(3) =30a(4) =210a(5) =2310a(6) =29464a(7) =476928a(8) =9671392a(9) =222388792a(10) =6438663000a(11) =200560490130