Erroneous version of A006749.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =9a(5) =19a(6) =84a(7) =316a(8) =1196a(9) =4461a(10) =16750a(11) =62878a(12) =237394a(13) =899265