Duplicate of A049029.

Terms

a(0) =1a(1) =5a(2) =1a(3) =45a(4) =15a(5) =1a(6) =585a(7) =255a(8) =30a(9) =1a(10) =9945a(11) =5175a(12) =825a(13) =50a(14) =1a(15) =208845a(16) =123795a(17) =24150