T(2*n,n), array T as in A054110.

Terms

a(0) =1a(1) =5a(2) =17a(3) =57a(4) =197a(5) =701a(6) =2549a(7) =9413a(8) =35153a(9) =132393a(10) =501905a(11) =1912769a(12) =7321081a(13) =28122281a(14) =108355481a(15) =418590521a(16) =1620751301a(17) =6287963741a(18) =24438234341a(19) =95128761941a(20) =370821819581