T(2n,n-3), T given by A026758.

Terms

a(0) =1a(1) =11a(2) =82a(3) =519a(4) =3010a(5) =16563a(6) =88092a(7) =457800a(8) =2340519a(9) =11824761a(10) =59217488a(11) =294596574a(12) =1458173626a(13) =7189542273a(14) =35341573246a(15) =173322863748a(16) =848473455491