Number of terms in a bordered skew determinant.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =13a(5) =41a(6) =226a(7) =1072a(8) =9059a(9) =58123a(10) =657766a(11) =5268836a(12) =73980787a(13) =707506879a(14) =11823958238a(15) =131277234376