T(2n+1,n+4), T given by A026780.

Terms

a(0) =1a(1) =10a(2) =68a(3) =396a(4) =2136a(5) =11062a(6) =56070a(7) =281306a(8) =1406721a(9) =7042818a(10) =35401568a(11) =178975192a(12) =910933936a(13) =4669860386a(14) =24114746282a(15) =125416122430a(16) =656713729000